JP2004339962A - Sealing structure of exhaust pipe in outboard motor - Google Patents

Sealing structure of exhaust pipe in outboard motor Download PDF

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Publication number
JP2004339962A
JP2004339962A JP2003135049A JP2003135049A JP2004339962A JP 2004339962 A JP2004339962 A JP 2004339962A JP 2003135049 A JP2003135049 A JP 2003135049A JP 2003135049 A JP2003135049 A JP 2003135049A JP 2004339962 A JP2004339962 A JP 2004339962A
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Japan
Prior art keywords
exhaust pipe
opening
cover member
seal
engine
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
JP2003135049A
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Japanese (ja)
Inventor
Makoto Yazaki
誠 矢崎
Shinichi Ide
真一 井手
Mitsuaki Kubota
美津明 久保田
Chu Yamamoto
宙 山本
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Honda Motor Co Ltd
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Honda Motor Co Ltd
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Filing date
Publication date
Application filed by Honda Motor Co Ltd filed Critical Honda Motor Co Ltd
Priority to JP2003135049A priority Critical patent/JP2004339962A/en
Priority to US10/839,412 priority patent/US6941921B2/en
Priority to CN200410034781.2A priority patent/CN1288035C/en
Publication of JP2004339962A publication Critical patent/JP2004339962A/en
Priority to US11/203,351 priority patent/US7294030B2/en
Pending legal-status Critical Current

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    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
    • F01N13/00—Exhaust or silencing apparatus characterised by constructional features ; Exhaust or silencing apparatus, or parts thereof, having pertinent characteristics not provided for in, or of interest apart from, groups F01N1/00 - F01N5/00, F01N9/00, F01N11/00
    • F01N13/12—Exhaust or silencing apparatus characterised by constructional features ; Exhaust or silencing apparatus, or parts thereof, having pertinent characteristics not provided for in, or of interest apart from, groups F01N1/00 - F01N5/00, F01N9/00, F01N11/00 specially adapted for submerged exhausting
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
    • F01N13/00—Exhaust or silencing apparatus characterised by constructional features ; Exhaust or silencing apparatus, or parts thereof, having pertinent characteristics not provided for in, or of interest apart from, groups F01N1/00 - F01N5/00, F01N9/00, F01N11/00
    • F01N13/004—Exhaust or silencing apparatus characterised by constructional features ; Exhaust or silencing apparatus, or parts thereof, having pertinent characteristics not provided for in, or of interest apart from, groups F01N1/00 - F01N5/00, F01N9/00, F01N11/00 specially adapted for marine propulsion, i.e. for receiving simultaneously engine exhaust gases and engine cooling water
    • F01N13/005—Exhaust or silencing apparatus characterised by constructional features ; Exhaust or silencing apparatus, or parts thereof, having pertinent characteristics not provided for in, or of interest apart from, groups F01N1/00 - F01N5/00, F01N9/00, F01N11/00 specially adapted for marine propulsion, i.e. for receiving simultaneously engine exhaust gases and engine cooling water with parts constructed of non-metallic material, e.g. of rubber
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
    • F01N13/00—Exhaust or silencing apparatus characterised by constructional features ; Exhaust or silencing apparatus, or parts thereof, having pertinent characteristics not provided for in, or of interest apart from, groups F01N1/00 - F01N5/00, F01N9/00, F01N11/00
    • F01N13/08—Other arrangements or adaptations of exhaust conduits
    • F01N13/085—Other arrangements or adaptations of exhaust conduits having means preventing foreign matter from entering exhaust conduit
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
    • F02M35/00—Combustion-air cleaners, air intakes, intake silencers, or induction systems specially adapted for, or arranged on, internal-combustion engines
    • F02M35/02—Air cleaners
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
    • F02M35/00—Combustion-air cleaners, air intakes, intake silencers, or induction systems specially adapted for, or arranged on, internal-combustion engines
    • F02M35/02—Air cleaners
    • F02M35/04—Air cleaners specially arranged with respect to engine, to intake system or specially adapted to vehicle; Mounting thereon ; Combinations with other devices
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
    • F02M35/00—Combustion-air cleaners, air intakes, intake silencers, or induction systems specially adapted for, or arranged on, internal-combustion engines
    • F02M35/10—Air intakes; Induction systems
    • F02M35/10091—Air intakes; Induction systems characterised by details of intake ducts: shapes; connections; arrangements
    • F02M35/10144—Connections of intake ducts to each other or to another device
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
    • F02M35/00—Combustion-air cleaners, air intakes, intake silencers, or induction systems specially adapted for, or arranged on, internal-combustion engines
    • F02M35/16—Combustion-air cleaners, air intakes, intake silencers, or induction systems specially adapted for, or arranged on, internal-combustion engines characterised by use in vehicles
    • F02M35/165—Marine vessels; Ships; Boats
    • F02M35/167—Marine vessels; Ships; Boats having outboard engines; Jet-skis
    • F02M35/168—Marine vessels; Ships; Boats having outboard engines; Jet-skis with means, e.g. valves, to prevent water entry
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
    • F01N2530/00—Selection of materials for tubes, chambers or housings
    • F01N2530/22—Flexible elastomeric material
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
    • F01N2590/00—Exhaust or silencing apparatus adapted to particular use, e.g. for military applications, airplanes, submarines
    • F01N2590/02—Exhaust or silencing apparatus adapted to particular use, e.g. for military applications, airplanes, submarines for marine vessels or naval applications
    • F01N2590/021—Exhaust or silencing apparatus adapted to particular use, e.g. for military applications, airplanes, submarines for marine vessels or naval applications for outboard engines
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
    • F02M35/00—Combustion-air cleaners, air intakes, intake silencers, or induction systems specially adapted for, or arranged on, internal-combustion engines
    • F02M35/10—Air intakes; Induction systems
    • F02M35/10091—Air intakes; Induction systems characterised by details of intake ducts: shapes; connections; arrangements
    • F02M35/10111—Substantially V-, C- or U-shaped ducts in direction of the flow path

Abstract

<P>PROBLEM TO BE SOLVED: To ensure an improved sealing property in an outboard motor by surely sealing the part between an engine cover and an exhaust pipe discharging exhaust gas to the outside, and surely absorbing a deviation between the exhaust pipe and an opening for taking out the exhaust pipe of the engine cover. <P>SOLUTION: In the outboard motor with an engine covered with a cover member, the exhaust pipe for discharging at least a part of exhaust gas of the engine in the air is provided to a main-body case, and an end of the exhaust pipe is protruded to the outside from the opening made in the cover member. A sealing means 30 for sealing the part between the cover member and the exhaust pipe is provided in the opening. The sealing means includes parts to be held by either one of the cover member or the exhaust pipe, 1st sealing parts 35, 35a, a 2nd sealing part 38 in contact with the exhaust pipe, and a deviation-absorbing part 40 placed between the parts to be held and either one of the sealing parts. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

【０００１】
【発明の属する技術分野】
本発明は、船外機の運転において、エンジン排気を外気に放出する排気管のシール構造に係り、特にエンジン排気圧が小さい場合にエンジン排気を外気に放出する排気管のシール構造関する。
【０００２】
【従来の技術】
船外機において、船外機の運転において、エンジンの始動時やアイドリング時のように、エンジン排気圧が小さい場合に排気を外気に放出する排気管（副排気管）を設ける技術は知られている（例えば、特許文献１参照）
【０００３】
【特許文献１】
特開平９−３９８９０号公報（［００１３］、［００２６］、［００２８］、［図４］）
【０００４】
特許文献１は船外機の排気レリーズ構造に係り、樹脂製のエンジンカバー１２（同公報中の符号を用いる。以下同じ）で覆われるエンジンルームと、下方のドライブシャフトハウジング８との間は、金属製のエンジンホルダ４、オイルシールハウジング５で上下に区画される。エンジンルーム側に配設されたエンジン排気系路と接続される上位の金属製エキゾーストチューブ４１とドライブシャフトハウジング８側に配設される金属製の第一排気膨張室３４（第一排気流路４２）との間をエンジンホルダ４に設けた第二排気孔４０で接続し、ドライブシャフトハウジング８下方に排気を排出する。
第二排気孔４０には船外機後方に開口する筒状の排気レリーズ通路４７を一体に設け、排気通路の一部を外気と連通させる。
【０００５】
以上においては、船外機の運転時にエンジンの排気圧が大きい場合には、第一排気流路４２から下方の水中に排気は排出されるが、エンジンの始動時やアイドリング時のようエンジンの排気圧が小さい場合には、前記した排気レリーズ通路４７から外気に排気を放出することができる。
ところで、前記した排気レリーズ通路４７はパイプ状の後端部をエンジンカバー１２の後方に露出して外気と連通させる必要があり、その後端部とエンジンカバー１２の挿通孔との間にパッキン４８（リング状のシール材）を介装してシールしている。
【０００６】
【発明が解決しようとする課題】
以上の従来技術は、金属製のエンジンホルダ４の一部にパイプ状の排気レリーズ通路４７を一体に設けており、該通路の後端部を樹脂製のエンジンカバー１２の後部に設けた挿通孔を貫通し、挿通孔と排気レリーズ通路４７の後端部との間にパッキン４８を介装しているが、エンジンカバー１２が樹脂製で外形が大きく、一方、排気レリーズ通路４７は金属製のエンジンホルダ４と一体に成形されており、排気レリーズ通路４７とエンジンカバー１２の挿通孔との中心がズレ易く、また夫々の製作誤差、組付誤差が不可避的に生じるが、これの吸収が難しい。この結果エンジンカバ１２ー及び挿通孔の精度を高精度に維持する必要があり、またエンジンホルダ４の位置精度を高精度に維持する必要があり、構成部品の製作、組付作業の点で手間がかかる。
【０００７】
また前述の従来技術では、詳細構造が不明であるが、挿通孔内周とリング状パッキンを介装しただけの構造では両者が近接するとパッキンは圧縮されるが、素材の限界に近づくとズレを吸収することができず、突っ張り、両者が離反するとパッキンの膨張によってのみ両者の間のズレを吸収するが、当接する圧力が下がり、高いシール性を得ることは難しい。
【０００８】
本発明は、以上の従来技術の課題を解決すべきなされたものである。
本発明の目的とする処は、船外機において、特にエンジンの排気圧が低い時に外気に排気を排出する排気管とエンジンカバーとの間のシール及びエンジンカバーの排気管導出開口と排気管との間のズレ吸収を確実に行なわせ、且つ高いシール性を確保し、またエンジンカバーと排気管との接続、該カバー外への導出構造を容易化し、また組付性を向上し得る船外機における排気管のシール構造を提供することにある。
【０００９】
【課題を解決するための手段】
上記目的を達成するために請求項１は、エンジンと、該エンジンで駆動されるプロペラとを備え、これらの一部を本体ケースで支持し、前記エンジンをカバー部材で覆った船外機において、前記エンジンの排気の少なくとも一部を空中に排気する排気管を前記本体ケースに設け、前記排気管の端部を、前記カバー部材に設けた開口部から外方に突き出すとともに、前記開口部には、前記カバー部材と前記排気管との間をシールするシール手段を備え、前記シール手段には、前記カバー部材または前記排気管の何れかに保持される保持部と、前記カバー部材に接する第１シール部と、前記排気管に接する第２シール部と、前記保持部と前記シール部の何れかとの間の偏寄吸収部（偏倚吸収部）とを備えることを特徴とする。
【００１０】
請求項１では、船外機において、排気管をカバー部材の外方に突き出す開口部に、カバー部材等に保持され、カバー部材と排気管との間をシールするシール手段を設け、シール手段をカバー部材または排気管の何れかに保持部で保持し、第１シール部で開口部周辺部をシールし、第２シール部で排気管をシールし、位相のズレは偏寄吸収部（偏倚吸収部）で吸収される。
偏寄とは偏りであり、偏寄吸収部とはこれを吸収する部分であり、偏倚とはそれ（逸れ）であり、偏倚吸収部とはこれを吸収する部分であり、偏寄吸収部の偏寄は、偏寄、偏倚はこの双方を含む概念である。
【００１１】
請求項２は、請求項１において、前記保持部は、前記カバー部材の開口部に対してシール手段を保持するように、前記カバー部材の開口部に概ね位置し、前記偏寄吸収部は、前記開口部を形成した面よりカバー部材内方または外方に設けられていることを特徴とする。
【００１２】
請求項２では、シール手段の保持部は、カバー部材の開口部周辺部でこれを保持し、偏寄吸収部はカバー部材の開口部の面よりも内方、または外方に設けられているのでズレ吸収部である撓み部分を容易に、ズレ吸収容量を大きく設定することができる。
【００１３】
請求項３は、請求項１において、前記保持部は、前記カバー部材の開口部に対してシール手段を保持するように、前記カバー部材の開口部に概ね位置し、前記シール部は、前記開口部を形成した面に概ねあり、前記偏寄吸収部がその面よりもカバー部材内方または外方に設けられていることを特徴とする。
【００１４】
請求項３では、シール手段の保持部は、カバー部材の開口部周辺部でこれを保持し、シール部は開口部を形成した面に配置されており、シール部の偏寄吸収部はカバー部材の開口部の面よりも内方、または外方に設けられているのでズレ吸収部である撓み部分を容易に、ズレ吸収容量を大きく設定することができる。
【００１５】
請求項４は、請求項１〜請求項３の何れかにおいて、前記偏寄吸収部は、撓みによるズレ吸収を行なうことを特徴とする。
【００１６】
請求項４では、偏寄吸収部が撓みによってズレ吸収を行なうので、排気管、シール手段、第１、第２シール部の間にズレに追従して、この間のズレを確実に、容易に吸収することができる。
【００１７】
請求項５は、請求項１〜請求項４の何れかにおいて、前記カバー部材が前記エンジンを収容するエンジンルームの一部を構成し、前記開口部が該エンジンルームに臨んで設けられており、前記排気管が該エンジンルーム内からカバー部材外方に前記開口部を貫通するように設けられており、前記シール部が前記開口部の縁から離間した箇所に設けられていることを特徴とする。
【００１８】
請求項５では、エンジンルームを一部であるカバー部材の開口部をシールするシール部材のシール部は、開口部の縁から離間した箇所に設けられているので、開口部周辺部から侵入する可能性のある水に対する防水性、耐侵入性に優れる。
【００１９】
請求項６は、請求項１において、前記ケース体はエンジンを支持するマウントケースであり、前記シール手段は前記カバー部材の開口部を閉塞するリッドであり、前記保持部は該リッドをカバー部材の開口部周辺部に固定する固定部材であり、前記第１シール部はカバー部材の裏面に設けられ、前記カバー部材の前記開口部を囲繞し、該開口部周辺部に接触するシール部であり、前記偏寄吸収部は、前記排気管を該リッドに対して可撓性をもって保持する構造であることを特徴とする。
【００２０】
請求項６では、カバー部材の開口部からマウントケースに支持された排気管を外部排気管として導出し、開口部をカバー部材に対し固定したリッドで閉塞し、カバー部材裏面の第１シール部で開口周辺部をシールし、第２シール部で排気管外周をシールし、偏寄吸収部は、排気管をリッドに対して可撓性をもって保持するので、この部分の撓みで、金属製のマウントケースに支持された排気管と、樹脂製のカバー部材との間に生じた位相ズレ（偏り、逸れ）を吸収することができる。
【００２１】
請求項７は、請求項６において、前記偏寄吸収部は、前記排気管に嵌合する筒状部であり、前記リッドの面に対し交わるように設けられ、該筒状部内周に前記排気管外周に接触する前記可撓性シールリップ部からなる第２シールを備え、該筒状部は、前記リッドと一体に形成したことを特徴とする。
【００２２】
請求項７では、カバー部材の開口を塞いでシールするリッドに設けた筒状部に排気管を通し、嵌合することで排気管をシールすることができ、筒状部がリッドに対して撓むので偏寄吸収部として金属製のマウントケースに支持された排気管と、樹脂製のカバー部材との間に生じた位相ズレ（偏り、逸れ）を筒状部の撓みで吸収することができる。
【００２３】
請求項８は、請求項１において、前記偏寄吸収部は、前記カバー部材にシール部を介して装着され、該偏寄吸収部と連続し、排気管を嵌合、保持する筒状部を備え、該筒状部内周に前記排気管外周に接触する可撓性シールリップ部からなる第２シールを備えることを特徴とする
【００２４】
請求項８では、カバー部材に設けた排気管導出開口部にシール部材をシール部を介して装着し、偏寄吸収部は排気管を嵌合、保持する筒状部との間で撓み、偏寄吸収部として金属製のマウントケースに支持された排気管と、樹脂製のカバー部材との間に生じた位相ズレ（偏り、逸れ）を筒状部の撓みで吸収することができる。
また可撓性シールリップ部で排気管と筒状部との間のシールを高度に維持することができる。
【００２５】
請求項９は、請求項７、または請求項８において、前記筒状部に設けた第２シール部の可撓性シールリップ部はリング状であり、排気管と接触する先端部が外方を向いて軸方向に離間して複数個設けられていることを特徴とする。
【００２６】
請求項９では、リング状の可撓性シールリップ部で排気管外周をいわば結束した状態とし、シールリップ部の先端部が外方を向いているので、エンジンルーム内の負圧が排気管を介して外方に作用しても、シールリップ部で高度のシール性が確保でき、外部に導出した排気管のシール部分の高い防水性を保障することができる。
【００２７】
請求項１０は、請求項６において、前記カバー部材の裏面に設けられた第１シール部は、前記開口部を囲繞し、該開口部の縁から離間した箇所に設けられてシールリップ部として形成され、該シールリップ部の該開口部周辺部と接触する先端部が該開口の外方に向いて設けられているようにしたことを特徴とする。
【００２８】
請求項１０では、カバー部材の裏面に設けられた第１シール部を開口部を囲繞し、開口部の縁から離間した箇所にシールリップ部として形成し、且つシールリップ部の開口部周辺部と接触する先端部が開口の外方に向いて設けられているようにしたので、カバー部材の開口部周辺部から侵入する可能性のある水に対する防水性、耐侵入性に優れる。
【００２９】
【発明の実施の形態】
本発明の実施の形態を添付図に基づいて以下に説明する。なお、図面は符号の向きに見るものとする。
本発明の実施の形態を添付図に基づいて以下に説明する。なお、図面は符号の向きに見るものとする。
図１は、要部を破断して示した船外機の説明的な全体側面図で、図においてＦｒは推進方向前方を、Ｒｒは推進方向後方を示す。図１は、船外機の一部を破断して示す側面図である。
船外機１は、エンジンを支持するケース体（本実施の形態ではマウントケースを含む）と、エンジンを覆い、エンジンルームを構成するカバーとからなる。これらについては後述する。
【００３０】
エンジン２はクランク軸２ａが縦向きのバーチカルエンジンで、複数のシリンダ、実施の形態では４つのシリンダ２ｂ，２ｂ，２ｂ，２ｂ（以下２ｂ…と記す。…は複数を表す。以下同じ）を平行に上下に並べて配置した複数気筒エンジンである。エンジン２の各シリンダ２ｂ…内にはピストン２ｃ，２ｃ，２ｃ，２ｃ（以下２ｃ…と記す。…は複数を表す。以下同じ）…を嵌装しており、前後方向中間部位でシリンダブロック２ｄを構成する。シリンダ中心線は船外機の前後方向を向く。
シリンダブロック２ｄの後方にはシリンダヘッド２ｅを、更にその後方にはシリンダヘッドカバー２ｆが設けられており、また、シリンダブロック２ｄの前方にはクランクケース２ｇが配設されている。以上のよりエンジン組立体を構成する。
【００３１】
エンジン２の各気筒のシリンダ２ｂ…、ピストン２ｃ…及びシリンダヘッド２ｅで燃焼室２ｈ…を構成する。
各燃焼室２ｈは、シリンダヘッド２ｅに設けた排気ポート２ｉ…に連通し、排気ポート２ｉに臨むようにシリンダヘッド２ｅの外側方には排気マニホールド３が縦向きに配設されている。エンジン２の下部にはオイルポンプボディを備える。
以上のエンジン組立体をマウントケース４でオイルケース５上に支持している。オイルケース５は、オイルパン部５ｃと後述の排気室１７とを形成するものであり、オイルパン部５ｃ内にオイル吸入管５ａ、オイルストレーナ５ｂが収容されている。
【００３２】
エンジン２の縦向きの前記したクランク軸２ａは、船外機全体としては図１の右側である前寄り部分に位置する。
クランク軸２ａの下端部には、不図示のフライホイールを介して出力軸２ｊを連結し、出力軸２ｊはマウントケース４を縦通し、縦向きに配置し、同軸上に配置した駆動軸６の上端部に連結されている。
【００３３】
駆動軸６は、下方のオイルパン５と周壁との間を通って下方に垂下し、延出され、伝動、変速機構７を介して後方を向くように配設された出力軸８ａを駆動する。
出力軸８ａの後端部にはプロペラ８を連結し、エンジン２で駆動軸７を駆動し、伝動、変速機構７を経由してプロペラ８を駆動することで推力を得る。
【００３４】
以上のエンジン２の上方及び周囲を樹脂製のエンジンカバー９で囲繞するように覆い、エンジンカバー９はエンジン２の上下方向の中間部〜上部を覆い、エンジン２の下半部〜ポンプボディを含むマウントケース４の周囲を及び上下を、エンジンカバー９の下方に配設した樹脂製のアンダーカバー１０で覆う。
前述のオイルケース５の下部には、エクステンションケース１１を連設し、エクステンションケース１１の下部にはギヤボックス１２を一体に設け、エクステンションケース１１及び変速機構７を内装したギヤボックス１２はアルミ合金等の金属で形成し、この内部の前寄り部分を前述の駆動軸６が縦通する。
アンダーカバー１０は、オイルケース５とエクステンションケース１１との合わせ面を覆う。
【００３５】
前記したポンプボディを含むマウントケース４及びその周辺部はアルミ合金等の金属で形成されている。このマウントケース４の前部及びエクステンションケース１１の前部の中間部との間にスイベル軸１３ａを縦設し、これにスイベルケース１３を介してスターンブラケット１４をチルト軸１４ａで上下回動可能に連結する。
即ち、船尾に固定したスターンブラケット１４に対し、チルト軸１４ａ廻りにスイベルケース１３がチルト運動し、従って、船外機１は船体の船尾に操舵可能に、チルト動（上下動）可能に取付支持される。
【００３６】
ところで、排気マニホールド３は、これの下部の下向きの排気部３ａをマウントケース４のオイルパン５の後方に隣接して縦通するように設けた連通口１５に連通接続し、該連通口１５を介して、マウントケース４の後部に下方に垂下、設置した排気管１６に該排気部３ａを連通、接続する。
これらで排気通路を形成する。
【００３７】
アンダーカバー１０内は前後方向に配設したマウントケース４で上下に区画され、マウントケース４の下方にエンジンルーム１８と上下に区画された空間を形成し、該空間に前記した排気管１６は垂下するように臨む。
かかる排気管１６の下方及び周囲の前記した空間で、排気膨張空間１７を形成する。マウントケース４で上下に区画されたエンジンルーム１８内の後部には、マウントケース４で区画された室（空間）１７，１８を連通する連通路１９を設ける。
【００３８】
連通路１９は、マウントケース４の後部４ａに縦通設置する。連通路１９には側面視略逆Ｌ形の排気管２０の基部をボルト止めにて装着する。
該排気管２０は、エンジン排気を外部に排出する外部排気管で、該外部排気管２０の略々水平に後方を向いて開口する後端部２０ａは，アンダーカバー１０の後面に設けた後述の開口５０から後外方に導出されている。
通常はエンジン排気は、排気マニホールド３から連通口１５を通って下方に垂下された排気管１６から排気膨張空間１７に排出され、エクステンションケース１１内を通って水中に排気は放出される。
【００３９】
尚、図示した実施の形態では、外部排気管２０をマウントケース４の後部に設けた連通路１９に接続したが、マウントケース４に代え、図１におけるオイルパン５の後部をフランジ部として後方に延長し、この延長部分に連通路を縦通設置し、これに外部排気管２０を接続配置しても良い。
【００４０】
ところで、アイドリング運転時のように、エンジンの排気圧が低い時は、排気の水中を通した放出が行えない。
一方、排気は、排気膨張空間１７内に排気管１６を介して排出される。この場合、排気は連通口１９を介して外部排気管２０からアンダーカバー１０の後方外部に排出されることとなる。
このように、外部排気管２０は、アイドリング運転時のように、エンジンの排気圧が低い時には、排気を該排気管２０から外部に排出する作用を行なう。
【００４１】
尚図１において２１は吸気通路装置で、２２は左右の吸気通路の上位の中間部の連結部２２で、図１では片側の吸気通路２４のみが表されているが、図では表われないが、他方の吸気通路は紙面表裏方向の手前側に配設されている。
またエンジンカバー９の頂部の後部に設けた２５は外気取入開口で、頂片部９ａの後部上端部に左右方向に細長い第１外気取入開口２５ａ、前後方向中間部の上向きに開口した第２外気取入開口２５ｂ、この前方のギャラリ状の第３外気取入開口２５ｃとからなる。
【００４２】
図２はアンダーカバーの後部の斜視図で、シール手段の取付直前の状態を示す分解斜視図である。
アンダーカバー１０は左右の半体１０Ｌ，１０Ｒからなり、後面の接合縁部１０ｃ，１０ｃの上部〜中間部には左右対称形状の凹部１０ａ，１０ａが形成されており、半体１０Ｌ、半体１０Ｒを接合一体化することで、後面に縦長の開口部５０を形成する。接合した半体１０Ｌ、半体１０Ｒの上端部には、上部のエンジンカバー９の下縁部と嵌合する係合片１０ｂが起立設置されている。
【００４３】
開口部５０の周辺部には座面５１が該開口部５０を囲繞するように設けられており、座面の四隅及び周辺部寄り部分には取付孔５２…が設けられている。
開口部５０の上部の大開口部５０ａにはエンジン２の最下位気筒の点火プラグ２ｐが臨み、下部の小開口部５０ｂには、前記した外部排気管２０の後端部２０ａが臨んでいる。
【００４４】
以上の開口部５０をシール手段で閉塞する。
シール手段は実施の形態ではリッド状であり、リッド３０を図２〜図５と併せて説明する。
図３は、シール手段であるリッドの船外機後方を向いた正面斜視図、図４は同背面斜視図、図５は同縦断面図である。これらの図面に従って説明すると、リッド３０は可撓性を有するゴムで形成する。
リッド３０は、前記した開口部５０を全面的に塞ぎ、且つ前記した座面５１を全面的に覆う板状をなす。
【００４５】
リッド３０の基板３１の表面３１ａには、上下に間隔を開けて実施の形態では５本の横向きの凹溝３２…を設け、長さ方向と直交する方向に撓み易くし、基板３１の上端部の左右及び下端部の左右並びに中間部の左右には、都合６個の取付孔３３…を備える。これによりシール手段であるリッドのアンダーカバー１０に対する保持部を形成する。
基板３１の裏面３１ｂの周縁部には、これを囲繞するように小さな縁状のリブ３４を設けるとともに、これの内側には、前記した開口部５０の周囲を囲繞するような縦長ループ状のシールリップ３５を一体に形成する。
【００４６】
縦長ループ状のシールリップ３５で第１のシール部を構成し、シールリップ３５は、開口部５０の開口縁から外側に間隔を開けて連続したループ状に形成されており、図５に示したように、シールリップ３５の先端部３５ａは外側を向くように斜めに形成されている。
また基板３１の裏面３１ｂの左右両側寄り部分で、上下の取付孔３３，３３間の中間部には、上下に間隔を開けて係止凸部３６…を都合４カ所設け、これについては後述する。
【００４７】
またリッド３０の基板３１の裏面３１ｂのシールリップ３５で囲まれた上部には、裏面方向に突出し、開口部５０の上部の大開口部５０ａに緊密に嵌合し、開口部を閉塞し、前記した最下位気筒の点火プラグ２ｐの工具挿入ための開口部５０ａに臨む部分に弾性的に当接し、シールする弾性シールブロック部３７を備える。
以上の基板３１の中間下部に、第２シール部である筒状部を構成する筒状シール部３８を、基板３１の表裏を貫通するように一体に設ける。
【００４８】
筒状シール部３８は、基板３１の表面３１ａへの突出量が裏面３１ｂのそれに対して少なく、図５で明らかなように、基板３１はアンダーカバー１０の後面の傾斜、即ち上部が船外機の後部に位置し、下部がこれよりも前方部に位置するので上部が後傾するように配置され、筒状シール部３８の軸線ｃは略々水平を向いて配置される。
筒状シール部３８の後部３８ａは表面３１ａへの突出量が少なく、大半は筒状本体部３９として裏面３１ｂに直線筒状にエンジンルーム内に所定長さ突出している。
【００４９】
リッド３０の基板３１の表面３１ａから後方に突出する後部３８ａは、開口面３８ｂが装着状態で、基板３１の面とほぼ平行するように斜めに設定されており、表面３１ａから少しく突出しており、開口３８ｃから水が侵入した際、入り難くし、且つ開口３８ｃの下半部３８ｄを後下方に傾斜させて基板３１の面に対し斜めの孔となる筒状部の成形時の型抜きを容易にしている。
尚、実施の形態では、図３及び図６に示したように、基板３１の表面３１ａから後方に突出する後部３８ａの開口部を若干縦長に形成した。
【００５０】
基板３１の裏面３１ｂから前方、即ち、エンジンルーム内に突出する筒状本体部３９は全長に亘り略々同径で、略々水平方向を向く筒状をなし、長さ方向の中間部〜前部にかけて径方向内方に突出するリング状のシールリップ４０…を軸方向に少しの間隔を開けて複数個備える。
筒状本体部３９の内周４０に設けた軸方向両端部のリング状の小径部４０ａ，４０ｂは、内径面が凸状である。この部分で排気管２０外周を保持する。
【００５１】
ところで筒状本体部３９の内周４０の前記した小径部４０ａ，４０ｂ間に設けた４０ｃ…は、複数個のリング状の可撓リップ部であり、実施例では３個の可撓リップ部４０ｃ，４０ｃ，４０ｃを軸方向に少し駆離間して設け、各リップ部４０ｃ，４０ｃ，４０ｃは、内径端部（先端部）が後方を向くように、且つ上述の小径部４０ａ，４０ｂよりも内径方向への突出量が大きく設定されている。
本体部３９の前端部の導入口４０ｄは、前方に（エンジンルーム方向）に向かって径が斜めに拡開するよう設定されている。
【００５２】
図２において、リッド３０の基板３１を裏面３１ｂアンダーカバー１０の後面の開口部５０側に向け、基板３１裏面３１ｂ周辺部を座面５１に当接させ、開口部５０を塞ぐように配置する。
リッド３０の裏面の弾性シールブロック部３７を、開口部５０の上部の大開口部５０ａに嵌合し、筒状シール部３８の前部の本体部３９を開口部５０の下部の小開口部５０ｂに隙間をもった状態で貫通し、該筒状シール部３８の本体部３９を後方を向いて配設されている外部排気管２０の後部２０ｂに嵌合する。
【００５３】
爾後、リッド３０を座面５１に押し付け、６カ所の取付孔３３…に係止ピン４１…を通して座面５１の上部左右の取付孔、中間部左右の取付孔、下部左右の６カ所の取付孔５２ａ…に通して係止し、一方、基板３１の裏面３１ｂに突設した前記の係止凸部３６…を中間部左右の取付孔５２ｂ…に通し、係止する。
これにより、リッド３０を開口部５０を閉塞しつつアンダーカバー１０後面の座面５１に取り付ける。
【００５４】
以上においては、筒状シール部３８の筒状本体部３８の内周４０の小径部４０ａ、４０ｂが、外部排気管２０の外周に当接し、筒状本体３９の内周４０との間のクリアランスを概ね一定に保つ。
このクリアランスにより、リップ４０，４０ｃ，４０ｃは、各々全周が概ね均一に外部排気管２０の外周と当接し、所定のシール性を確保する。
また筒状本体部３９全体がリッド３０の基板３１に対して撓んで揺動し、また筒状部自体も撓み、これにより従来のパッキンのように開口部５０の縁との間で突っ張ることも、間伸びすることもない。
【００５５】
以上のリッド３０の基板裏面に設けたるシールリップ３５で第１シールを構成し、筒状シール３９の筒状本体３９が基板３１に対して撓み、また筒状本体自体の撓みで偏寄吸収部を構成する。
また、内周４０に形成した前記したシールリップ４０，４０ｃ，４０ｃで第２シール部を構成する。
【００５６】
図６は、上記したリッド３０を取り付けた状態のアンダーカバー１０を後方から見た図である。
以下に取付状態を説明する。
図７は、図６の７−７線断面図で係止ピンの係止途中の図、図８は係止ピンによる係止状態を示す図である。
取付孔３３及び５２ａに拡開クリップ４２を挿通し、拡開クリップ４２は外端部にフランジ部４２ａを備え、リッド３０側の取付孔３３の外端部に設けた凹部３３ａで、該クリップ４２のフランジ部４２ａを支持する。
この状態を図７で示した。
【００５７】
拡開クリップ４２に係止ピン４１の軸部４１ａを挿入し、これを押し込むことで拡開クリップ４２の狭窄部４２ｂが拡開し、図８に示すように拡開クリップ４２の先端部４２ｃは座面５１側の取付孔５２ａ…のカバー内側で該孔径よりも十分に膨大化し、抜け出しが規制される。
リッド３０の裏面に形成した外周のリブ３４は弾性的に変形して座面５１の周辺部に密着してシールし、また内側のシールリップ３５は弾性的に変形して座面５１に当接し、その先端部３５ａは外側を向いて座面５１に密着し、高いシール効果を得る。
【００５８】
図９は、図６の９−９線断面図で係止凸部による係止直前の図、図１０は係止凸部による係止状態を示す図である。
リッド３０の基板３１裏面に突設した係止凸部３６…は、図９に示すように開口部５０の座面５１に形成した取付孔５２ｂ…の内径よりも若干小径の首部３６ｃと、取付孔５２ｂよりも十分に大径の逆台形状の係止部３６ａと、該係止部３６ａの内部に形成され、先端部に開放した凹部３６ｂとからなる。
【００５９】
リッド３０を座面５１に当接、密着させる際、係止凸部３６…を取付孔５２ｂ…に嵌合する。係止凸部３６…は係止部３６ａが取付孔５２ｂの内径よりも十分に大きいが、挿入に際し径方向内方に撓み、取付孔５２ｂ…内に侵入する。
侵入に際し、係止部３６ａは凹部３６ｂにより径方向内方に容易に撓み、取付孔５２ｂ…内に嵌合し、首部３６ｃが取付孔５２ｂ内に臨む。
【００６０】
図１０に示すように、径方向内方に撓んで取付孔５２ｂ内を通過した大径の係止部３６ａは、外形の拘束を離れ、元の形状に膨径化して取付孔５２ｂの座面５１裏面側に突出するので、取付孔５２ｂからの抜け出しは阻止されることとなる。
ところで、前記したシールリップ３５は座面５１に弾性的に密着し、その先端部３５ａは外側に拡がって密着し、また外周縁の弾性リブ３４は座面５１周辺部に弾性的に接触して密着し、内外２重のシール構造となる。
【００６１】
図１１は、外部排気管２０のリッド３０に形成した筒状シール部３８への嵌合、シール状態を示す要部拡大縦断側面図である。
前記した通り、リッド３０を開口部５０を閉塞すべく座面５１に取り付ける際、外部排気管２０の後部に筒状シール部３８を挿通する。挿通に際し、筒状本体部３９の前端部の導入口４０ｄは、前方に（エンジンルーム方向）に向かって拡開しているので、外部排気管２０の後端部２０ａの挿入は容易に、円滑に、確実に行うことができる。
【００６２】
外部排気管２０の外周部２０ｂは、筒状本体部３９の内周に形成したシールリップ４０の前部のリング状の小径部４０ｂを押圧して弾性変形させ、軸方向外方の複数個のリング状の可撓リップ部４０ｃ…を後方（外側方向）に撓ませつつ内周部を進行し、小径部４０ａを経てその後端部が筒状シール部３８の後部３８ａに臨む。
外部排気管２０の後端面２０ｃは、筒状シール部３８の後端の開口３８ｃよりも少しく外部に突出する。
【００６３】
上記においては、筒状シール部３６内において、外部排気管２０の外周部２０ｂは、小径部４０ａ，４０ｂによって筒状シール部内周面と外部排気管２０の外周部２０ｂとの距離を略均一に保ち、この間の可撓リップ部４０ｃ，４０ｃ，４０ｃが概ね均一に外周部２０ｂに当接し、シールし、且つ可撓リップ部４０ｃ，４０ｃ，４０ｃは外方（カバーの外側）を向くように撓んでおり、エンジンルーム１８内が負圧になったとしても、シール性を高度に維持し、確保することができる。
【００６４】
図１２は、本発明のシール構造の他の実施の形態を示す縦断側面図である。
本実施の形態は、船外機のカバー部材１３０とシール部材１３８とを別体で形成し、一体化したものである。シール部材は可撓性を有するゴムで形成する。
船外機のカバー体１３０には貫通孔１３０ａを設けておき、これにシール部材１３８の周辺部を嵌合、一体化したものである。
シール部材１３８は中央部に筒状部１３９を有し、筒状部の後端部に一体の前方（エンジンルーム１８方向、カバー内側）に向けて拡開した傘状で、軸方向に長さを有する周辺部１３８ｂを備える、周辺部１３８ｂの外周にリング状凹溝１４１を設け、該リング状凹溝１４１をカバー部材１３０の貫通孔１３０ａ内周に嵌め込んで装着し、周辺部１３８ｂをシール性を保持しつつカバー部材１３０に装着したものである。
【００６５】
また本実施の形態では、カバーの貫通孔周辺に対するシール構成が簡便なものになっているが、貫通孔が、カバー体のマウントケースによって区画される下側の範囲、つまりエンジンルーム外において設けられ、排気管２０が排気室１７から突出している場合のように、エンジンの吸気負圧が影響しない条件下では、効果的にシール機能を維持しながら安価な構成とすることができる。
【００６６】
周辺部１３８ｂと筒状部１３９の後端部間には、この間を繋ぐ連結部１３８ｃが形成され、連結部１３８ｃの部分の周辺部１３８の後端部及び筒状部１３９の後端部が屈曲して一体に連結し、この部分で筒状部１３９が周辺部１３８ｂに対して容易に撓み、該連結部１３８ｃで偏寄吸収部を構成する。
ところで、筒状部１３９の内周部１４０には、前記したと同様の可撓性リップ部１４０ｃ，１４０ｃ，１４０ｃ及び小径部１４０ｂを備え、挿入した外部排気管２０を保持し、シールしている。
【００６７】
以上、図示した実施の形態を説明した。実施の形態ではシール手段をカバー部材であるアンダーカバーの開口部に取り付けたが、これに代え、外部排気管側に取付支持しても良い。
またシール手段をリッド、或いはカバー部材開口部に嵌め込む部材としたが、具体的な形状や構造は任意であり、要すればカバー部材または外部排気管の何れかに取り付けることができ、シール部を備え、偏寄吸収部を備えれば良い。
また排気管は、マウントケースに嵌合し、位置決めを確実にしても良い。この場合でも、樹脂製のカバー体の撓みに対するズレの吸収が達成される。
尚、排気は、全部が大気中に放出される形式のもでも良い。
【００６８】
【発明の効果】
本発明は上記構成により次の効果を発揮する。
請求項１は、船外機の排気管のシール構造であって、エンジンと、該エンジンで駆動されるプロペラとを備え、これらの一部を本体ケースで支持し、エンジンをカバー部材で覆った船外機において、エンジンの排気の少なくとも一部を空中にする排気管を本体ケースに設け、排気管の端部を、カバー部材に設けた開口部から外方に突き出すとともに、開口部には、カバー部材と排気管との間をシールするシール手段を備え、シール手段には、カバー部材または排気管の何れかに保持される保持部と、カバー部材に接する第１シール部と、排気管に接する第２シール部と、保持部と前記シール部の何れかとの間の偏寄吸収部とを備える。
【００６９】
請求項１では、船外機において、排気管をカバー部材の外方に突き出す開口部に、カバー部材等に保持され、カバー部材と排気管との間をシールするシール手段を設け、シール手段をカバー部材または排気管の何れかに保持部で保持し、第１シール部で開口部周辺部をシールし、第２シール部で排気管をシールし、位相のズレは偏寄吸収部で吸収される。
シール手段とカバー部材との間の保持部、カバー部材と第１シール部との間、排気管と第２シール部との間に何れかの偏寄吸収部で、樹脂製のカバー部材と金属製の基台に設置される排気管との間のシール手段に製作誤差、組付け誤差等の誤差が発生しても、これら誤差を吸収し、カバー部材と外部排気を行なう排気管との間の高度のシール性を確保することができる。
そして、撓み部等の偏寄吸収部を設けるだけで上記を達成できるので、構造簡素に効果的な位相ズレ吸収、高精度のシールが行える。
【００７０】
請求項２は、請求項１において、保持部はカバー部材の開口部に対してシール手段を保持するように、カバー部材の開口部に概ね位置し、偏寄吸収部は、開口部を形成した面よりカバー部材内方または外方に設けられていることを特徴とする。
【００７１】
請求項２では、請求項１の効果に加えるに、シール手段の保持部は、カバー部材の開口部周辺部でこれを保持し、偏寄吸収部はカバー部材の開口部の面よりも内方、または外方に設けられているのでズレ吸収部である撓み部分を容易に、ズレ吸収容量を大きく設定することができる。
従って、樹脂製カバー部材の製作誤差、金属製基台との間の組付け誤差等の誤差が発生しても、これら誤差を吸収し、カバー部材と外部排気を行なう排気管との間の高度のシール性を確保することができる。
【００７２】
請求項３は、請求項１において、保持部はカバー部材の開口部に対してシール手段を保持するように、カバー部材の開口部に概ね位置し、シール部は、開口部を形成した面に概ねあり、偏寄吸収部がその面よりもカバー部材内方または外方に設けられているようにした。
【００７３】
請求項３では、請求項１の効果に加えるに、シール手段の保持部は、カバー部材の開口部周辺部でこれを保持し、シール部は開口部を形成した面に配置されており、シール部の偏寄吸収部はカバー部材の開口部の面よりも内方、または外方に設けられているのでズレ吸収部である撓み部分を容易に、ズレ吸収容量を大きく設定することができる。
従って、樹脂製カバー部材の製作誤差、金属製基台との間の組付け誤差等の誤差が発生しても、これら誤差を吸収し、カバー部材と外部排気を行なう排気管との間の高度のシール性を確保することができる。
【００７４】
請求項４は、請求項１〜請求項３の何れかにおいて、前記偏寄吸収部は、撓みによるズレ吸収を行なうことを特徴とする。
【００７５】
請求項４では、請求項１〜請求項３の何れか効果に加えるに、偏寄吸収部が撓みによってズレ吸収を行なうので、排気管、シール手段、第１、第２シール部の間にズレに容易に追従して、この間のズレを確実に、容易に吸収することができる。
従って、樹脂製カバー部材の製作誤差、金属製基台との間の組付け誤差等の誤差が発生しても、これら誤差を吸収し、カバー部材と外部排気を行なう排気管との間の高度のシール性を確保することができるとともに、ズレ吸収部を撓み構造としたので、構造が簡素で、高度の、確実なズレ吸収作用を得ることができる。
【００７６】
請求項５は、請求項１〜請求項４の何れかにおいて、カバー部材がエンジンを収容するエンジンルームの一部を構成し、開口部が該エンジンルームに臨んで設けられており、排気管が該エンジンルーム内からカバー部材外方に開口部を貫通するように設けられており、シール部が開口部の縁から離間した箇所に設けられているようにした。
【００７７】
請求項５では、エンジンルームを一部であるカバー部材の開口部をシールするシール部材のシール部は、開口部の縁から離間した箇所に設けられているので、開口部とシール部との間に十分の空間が形成される。従って、カバー部材の開口部周辺部からシール部を介して侵入する可能性のある水は、開口部との間に広い空間を経由してのみ侵入するので、シール手段の高度の防水性、耐親水性を得ることができる。
【００７８】
請求項６は、請求項１において、ケース体はエンジンを支持するマウントケースであり、シール手段はカバー部材の開口部を閉塞するリッドであり、保持部は該リッドをカバー部材の開口部周辺部に固定する固定部材であり、第１シール部はカバー部材の裏面に設けられ、カバー部材の開口部を囲繞し、該開口部周辺部に接触するシール部であり、偏寄吸収部は、排気管を該リッドに対して可撓性をもって保持する構造とした。
【００７９】
請求項６では、請求項１の効果に加うるに、カバー部材の開口部からマウントケースに支持された排気管を外部排気管として導出し、開口部をカバー部材に対し固定したリッドで閉塞し、カバー部材裏面の第１シール部で開口周辺部をシールし、第２シール部で排気管外周をシールし、偏寄吸収部は、排気管をリッドに対して可撓性をもって保持するので、この部分の撓みで、金属製のマウントケースに支持された排気管と、樹脂製のカバー部材との間に生じた位相ズレ（偏り、逸れ）を吸収することができる。
従って、カバー部材の開口部にリッドを閉塞するように取り付け、リッドに設けた第１シール部で開口をシールし、偏寄吸収部で排気管をリッドに対して可撓性をもって保持し、第２シール部で排気管外周をシールするので、構造簡素に、最少の部品で、カバー部材外に排気する排気管のシールを高度に実行することができる。
【００８０】
請求項７は、請求項６において、偏寄吸収部は、排気管に嵌合する筒状部であり、リッドの面に対し交わるように設けられ、筒状部内周に排気管外周に接触する可撓性シールリップ部からなる第２シールを備え、筒状部は記リッドと一体に形成した。
【００８１】
請求項７では、請求項６の効果に加えるに、カバー部材の開口を塞いでシールするリッドに設けた筒状部に排気管を通し、嵌合することで排気管をシールすることができ、筒状部がリッドに対して撓むので偏寄吸収部として金属製のマウントケースに支持された排気管と、樹脂製のカバー部材との間に生じた位相ズレ（偏り、逸れ）を筒状部の撓みで吸収することができる。
従って、排気管の外部導出に際し高いシール性が得られるとともに、筒状部で偏寄吸収部を構成し、筒状部内周に第２シール部として排気管外周に接触する可撓性シールリップ部を一体に設ければ良いので、偏寄吸収部及び第２シール部の構造が簡素で、容易に製作することができ、また偏寄吸収部である筒状部内周に排気管外周に接触する可撓性シールリップ部を設けてこれでシールし、且つ筒状部の撓みで排気管の位相ズレ（偏り、逸れ）吸収を行なうので、効果的なズレ吸収構造を得ることができる。
【００８２】
請求項８は、請求項１において、偏寄吸収部は、カバー部材にシール部を介して装着され、偏寄吸収部と連続し、排気管を嵌合、保持する筒状部を備え、筒状部内周に排気管外周に接触する可撓性シールリップ部からなる第２シールを備えるようにした。
【００８３】
請求項８では、請求項１の効果に加えるに、カバー部材に設けた排気管導出開口部にシール部材をシール部を介して装着し、偏寄吸収部は排気管を嵌合、保持する筒状部との間で撓み、偏寄吸収部として金属製のマウントケースに支持された排気管と、樹脂製のカバー部材との間に生じた位相ズレ（偏り、逸れ）を筒状部の撓みで吸収することができる。
また可撓性シールリップ部で排気管と筒状部との間のシールを高度に維持することができる。
そして、内部にシールリップを設けた筒状部の一部の周に円盤状に偏寄吸収部を設け、これの外周にシール部を設けたケース部材の開口部に嵌合、装着すれば良いので、構造簡素に、取付作業簡易に、機能的に極めて優れた船外機における排気管のシール構造を得ることができる。
【００８４】
請求項９は、請求項７または請求項８において、筒状部に設けた第２シール部の可撓性シールリップ部はリング状であり、排気管と接触する先端部が外方を向いて軸方向に離間して複数個設けた。
【００８５】
請求項９では、請求項７または請求項８の効果に加えるに、リング状の可撓性シールリップ部で排気管外周をいわば結束した状態とし、結束も軸方向に離間して複数箇所となり、そしてシールリップ部の先端部が外方を向いているので、エンジンルーム内の負圧が排気管を介して外方に作用しても、シールリップ部が内側に捲れることがなく、シールリップによる高度のシール性が確保でき、外部に導出した排気管のシール部分の高い防水性を保障することができる。
また以上を複数個のシールリップを筒状部の内周にリング状に設け、先端部を軸方向外方に向ければよく、構造が簡素で、製作も容易である。
【００８６】
請求項１０は、請求項６において、カバー部材の裏面に設けられた第１シール部は開口部を囲繞し、開口部の縁から離間した箇所に設けられてシールリップ部として形成され、シールリップ部の該開口部周辺部と接触する先端部が該開口の外方に向いて設けられているようにした。
【００８７】
請求項１０では、カバー部材の裏面に設けられた第１シール部を開口部を囲繞し、開口部の縁から離間した箇所にシールリップ部として形成し、且つシールリップ部の開口部周辺部と接触する先端部が開口の外方に向いて設けられているようにしたので、カバー部材の開口部周辺部から侵入する可能性のある水に対する防水性、耐侵入性に優れる。
また以上を、リッドの裏面にシールリップ部として開口部の縁から離間した箇所に形成し、且つシールリップ部の開口部周辺部と接触する先端部を、開口の外方に向くように形成すれば良いので、構造簡素に、製作容易に高度のシール性を確保し得るシール手段を得ることができる。
【図面の簡単な説明】
【図１】要部を破断して示した船外機の説明的な全体側面図
【図２】アンダーカバーの後部の斜視図で、シール手段の取付直前の状態を示す分解斜視図
【図３】シール手段であるリッドの船外機後方を向いた正面斜視図
【図４】リッドの背面斜視図
【図５】リッドの縦断面図
【図６】シール手段であるリッドを取り付けた状態のアンダーカバーを後方から見た図
【図７】図６の７−７線断面図で係止ピンの係止途中の図
【図８】図７における係止ピンによるリッドの係止状態を示す図
【図９】図６の９−９線断面図で係止凸部による係止手前の図
【図１０】図９における係止凸部による係止状態を示す図
【図１１】外部排気管のリッドに形成した筒状シール部への嵌合、シール状態を示す要部拡大縦断面図
【図１２】シール部材の他の実施の形態を示す縦断側面図
【符号の説明】
１…船外機、 ２…エンジン、 ８…プロペラ、 ４…本体ケースであるマウントケース、 ９，１０…カバー部材、 ２０…排気管である外部排気管、 ５０…開口部、 ３０…シール手段であるリッド、 ３３，３６，４１…保持部、３５…第１シール部、 ３８…第２シール部、 ３９…偏寄吸収部、 ４０ｃ…シールリップ部。[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a seal structure of an exhaust pipe that discharges engine exhaust to the outside air during operation of an outboard motor, and particularly to a seal structure of an exhaust pipe that discharges engine exhaust to the outside air when the engine exhaust pressure is low.
[0002]
[Prior art]
2. Description of the Related Art In an outboard motor, a technique for providing an exhaust pipe (sub exhaust pipe) that discharges exhaust gas to the outside air when engine exhaust pressure is low, such as when starting an engine or idling, is known. (For example, see Patent Document 1)
[0003]
[Patent Document 1]
JP-A-9-39890 ([0013], [0026], [0028], [FIG. 4])
[0004]
Patent Document 1 relates to an exhaust release structure of an outboard motor, in which a space between an engine room covered with a resin engine cover 12 (the reference numeral in the publication is used, the same applies hereinafter) and a lower drive shaft housing 8 is provided. It is vertically divided by a metal engine holder 4 and an oil seal housing 5. A metal upper exhaust tube 41 connected to the engine exhaust system disposed on the engine room side and a metal first exhaust expansion chamber 34 (first exhaust passage 42) disposed on the drive shaft housing 8 side. ) Is connected through a second exhaust hole 40 provided in the engine holder 4, and exhaust gas is exhausted below the drive shaft housing 8.
The second exhaust hole 40 is integrally provided with a cylindrical exhaust release passage 47 that opens to the rear of the outboard motor, and communicates a part of the exhaust passage with the outside air.
[0005]
In the above description, when the exhaust pressure of the engine is high during operation of the outboard motor, the exhaust gas is discharged from the first exhaust passage 42 into the water below, but the exhaust gas is discharged when the engine is started or idling. When the air pressure is low, exhaust gas can be discharged from the exhaust release passage 47 to the outside air.
The exhaust release passage 47 needs to have a pipe-shaped rear end exposed to the rear of the engine cover 12 to communicate with the outside air, and a packing 48 (between the rear end and the insertion hole of the engine cover 12). (A ring-shaped sealing material) is interposed.
[0006]
[Problems to be solved by the invention]
In the prior art described above, a pipe-shaped exhaust release passage 47 is integrally provided in a part of a metal engine holder 4, and a rear end of the passage is formed in an insertion hole provided in a rear portion of a resin engine cover 12. , And a packing 48 is interposed between the insertion hole and the rear end of the exhaust release passage 47. The engine cover 12 is made of resin and has a large outer shape. On the other hand, the exhaust release passage 47 is made of metal. Since it is formed integrally with the engine holder 4, the center between the exhaust release passage 47 and the insertion hole of the engine cover 12 is likely to be displaced. In addition, manufacturing errors and assembly errors are inevitably generated, but it is difficult to absorb them. . As a result, it is necessary to maintain the accuracy of the engine cover 12 and the insertion hole with high accuracy, and it is necessary to maintain the position accuracy of the engine holder 4 with high accuracy, which is troublesome in manufacturing and assembling components. It takes.
[0007]
In addition, in the above-mentioned conventional technology, the detailed structure is unknown, but in a structure in which the inner periphery of the insertion hole and the ring-shaped packing are merely interposed, the packing is compressed when the two are close to each other, but the gap is reduced when approaching the limit of the material. If they cannot be absorbed, they are stretched, and if they are separated from each other, the gap between them is absorbed only by the expansion of the packing. However, the contact pressure is reduced, and it is difficult to obtain high sealing performance.
[0008]
The present invention has been made to solve the above-mentioned problems of the prior art.
An object of the present invention is to provide a seal between an engine cover and an exhaust pipe that discharges exhaust gas to the outside air when the exhaust pressure of the engine is low, and an exhaust pipe outlet opening and an exhaust pipe of the engine cover, particularly in an outboard motor. Outboard that can reliably absorb the gap between the two and ensure high sealing performance, and also facilitate the connection between the engine cover and the exhaust pipe and the structure to lead out of the cover, and improve the assemblability. An object of the present invention is to provide a seal structure of an exhaust pipe in a machine.
[0009]
[Means for Solving the Problems]
To achieve the above object, the present invention provides an outboard motor including an engine, a propeller driven by the engine, a part of which is supported by a main body case, and the engine covered by a cover member. An exhaust pipe for exhausting at least a part of the exhaust of the engine into the air is provided in the main body case, and an end of the exhaust pipe projects outward from an opening provided in the cover member, and the opening has A sealing unit that seals between the cover member and the exhaust pipe, wherein the sealing unit includes a holding unit that is held by either the cover member or the exhaust pipe, and a first part that is in contact with the cover member. It is characterized by including a seal portion, a second seal portion in contact with the exhaust pipe, and a bias absorption portion (bias absorption portion) between the holding portion and any of the seal portions.
[0010]
According to the first aspect, in the outboard motor, at an opening that protrudes the exhaust pipe to the outside of the cover member, a sealing means that is held by the cover member or the like and seals between the cover member and the exhaust pipe is provided. The first sealing portion seals the periphery of the opening, the second sealing portion seals the exhaust pipe, and the phase difference is reduced by the bias absorbing portion (the bias absorbing portion). Part).
The deviation is a deviation, the deviation absorbing part is a part that absorbs the deviation, the deviation is that (deviation), the deviation absorbing part is a part that absorbs the deviation, and the deviation absorbing part is a part of the deviation absorbing part. Deviation is a concept that includes both deviation and deviation.
[0011]
Claim 2 is the device according to claim 1, wherein the holding portion is located substantially at the opening of the cover member so as to hold the sealing means with respect to the opening of the cover member, and the bias absorbing portion is The cover member is provided inside or outside the cover member from the surface where the opening is formed.
[0012]
According to the second aspect, the holding portion of the sealing means holds the portion around the opening of the cover member, and the offset absorbing portion is provided inside or outside the surface of the opening of the cover member. Therefore, it is possible to easily set the displacement absorbing capacity of the bent portion as the displacement absorbing portion.
[0013]
According to a third aspect of the present invention, in the first aspect, the holding portion is positioned substantially at the opening of the cover member so as to hold the sealing means with respect to the opening of the cover member, and the sealing portion is provided at the opening of the cover member. The offset absorbing portion is generally provided on the surface on which the portion is formed, and the offset absorbing portion is provided inside or outside the cover member with respect to the surface.
[0014]
According to the third aspect, the holding portion of the sealing means holds it around the opening of the cover member, and the sealing portion is disposed on the surface where the opening is formed. Since it is provided inside or outside of the surface of the opening, the displacement absorbing capacity can be easily set to be large for the bent portion which is the displacement absorbing portion.
[0015]
A fourth aspect of the present invention is characterized in that, in any one of the first to third aspects, the offset absorbing portion absorbs displacement due to bending.
[0016]
According to the fourth aspect, since the offset absorbing portion absorbs the displacement by bending, the displacement follows the displacement between the exhaust pipe, the sealing means, and the first and second seal portions, and the displacement therebetween is reliably and easily absorbed. can do.
[0017]
According to claim 5, in any one of claims 1 to 4, the cover member constitutes a part of an engine room accommodating the engine, and the opening is provided facing the engine room, The exhaust pipe is provided from the inside of the engine room to the outside of the cover member so as to penetrate the opening, and the seal portion is provided at a position separated from an edge of the opening. .
[0018]
According to the fifth aspect, since the seal portion of the seal member that seals the opening of the cover member that is a part of the engine room is provided at a position separated from the edge of the opening, it can enter from the periphery of the opening. Excellent waterproof and penetrating resistance to water.
[0019]
According to a sixth aspect of the present invention, in the first aspect, the case body is a mount case that supports an engine, the sealing unit is a lid that closes an opening of the cover member, and the holding unit is configured to connect the lid to the cover member. A fixing member fixed to a periphery of the opening, wherein the first seal portion is provided on a back surface of the cover member, surrounds the opening of the cover member, and is a seal portion that contacts the periphery of the opening; The offset absorbing portion has a structure in which the exhaust pipe is held with flexibility to the lid.
[0020]
According to the sixth aspect, the exhaust pipe supported by the mount case is led out from the opening of the cover member as an external exhaust pipe, and the opening is closed with a lid fixed to the cover member. The periphery of the opening is sealed, and the outer periphery of the exhaust pipe is sealed with the second seal part. The bias absorbing part holds the exhaust pipe with flexibility with respect to the lid. It is possible to absorb a phase shift (bias, deviation) generated between the exhaust pipe supported by the case and the resin cover member.
[0021]
According to a seventh aspect of the present invention, in the sixth aspect, the offset absorbing portion is a tubular portion fitted to the exhaust pipe, and is provided so as to intersect with a surface of the lid. A second seal comprising the flexible seal lip portion which comes into contact with the outer periphery of the pipe is provided, and the tubular portion is formed integrally with the lid.
[0022]
According to the seventh aspect, the exhaust pipe can be sealed by passing the exhaust pipe through a cylindrical portion provided on the lid for sealing by closing the opening of the cover member, and the cylindrical portion is bent with respect to the lid. Therefore, a phase shift (bias or deviation) generated between the exhaust pipe supported by the metal mount case as the deviation absorbing portion and the resin cover member can be absorbed by the deflection of the cylindrical portion. .
[0023]
According to claim 8, in claim 1, the offset absorbing portion is attached to the cover member via a seal portion, and is connected to the offset absorbing portion, and has a cylindrical portion that fits and holds an exhaust pipe. And a second seal formed of a flexible seal lip in contact with the outer periphery of the exhaust pipe on the inner periphery of the cylindrical portion.
[0024]
In the eighth aspect, a seal member is attached to the exhaust pipe lead-out opening provided in the cover member via a seal portion, and the bias absorbing portion is bent between the cylindrical portion for fitting and holding the exhaust pipe, and The phase shift (deviation or deviation) generated between the exhaust pipe supported by the metal mount case as the absorbing part and the resin cover member can be absorbed by the deflection of the cylindrical part.
Moreover, the seal between the exhaust pipe and the tubular portion can be maintained at a high level by the flexible seal lip.
[0025]
In a ninth aspect, in the seventh or eighth aspect, the flexible seal lip portion of the second seal portion provided on the cylindrical portion has a ring shape, and a tip portion that contacts the exhaust pipe is directed outward. It is characterized in that a plurality thereof are provided so as to face each other in the axial direction.
[0026]
According to the ninth aspect, the outer periphery of the exhaust pipe is bound so as to be so-called with a ring-shaped flexible seal lip, and the tip of the seal lip faces outward. Even if it acts outward through the seal lip, a high degree of sealing performance can be ensured at the seal lip portion, and high sealing performance of the sealing portion of the exhaust pipe led out can be ensured.
[0027]
According to a tenth aspect, in the sixth aspect, the first seal portion provided on the back surface of the cover member surrounds the opening and is provided at a position separated from an edge of the opening to form a seal lip portion. The seal lip is provided such that a tip portion of the seal lip that comes into contact with the periphery of the opening is provided to face outward of the opening.
[0028]
According to the tenth aspect, the first seal portion provided on the back surface of the cover member surrounds the opening, is formed as a seal lip at a position separated from the edge of the opening, and has a peripheral portion around the opening of the seal lip. Since the contact tip is provided so as to face the outside of the opening, the cover member is excellent in waterproofness and intrusion resistance against water that may enter from the periphery of the opening of the cover member.
[0029]
BEST MODE FOR CARRYING OUT THE INVENTION
An embodiment of the present invention will be described below with reference to the accompanying drawings. The drawings should be viewed in the direction of reference numerals.
An embodiment of the present invention will be described below with reference to the accompanying drawings. The drawings should be viewed in the direction of reference numerals.
FIG. 1 is an explanatory overall side view of an outboard motor in which essential parts are cut away, in which Fr indicates forward in the propulsion direction and Rr indicates rear in the propulsion direction. FIG. 1 is a side view showing a part of the outboard motor cut away.
The outboard motor 1 includes a case body (including a mount case in the present embodiment) that supports the engine, and a cover that covers the engine and forms an engine room. These will be described later.
[0030]
The engine 2 is a vertical engine in which a crankshaft 2a is vertically oriented, and a plurality of cylinders, in the embodiment, four cylinders 2b, 2b, 2b, 2b (hereinafter, referred to as 2b... Represents a plurality, and the same applies hereinafter). This is a multi-cylinder engine arranged vertically. Each of the cylinders 2b of the engine 2 is fitted with a piston 2c, 2c, 2c, 2c (hereinafter referred to as 2c... Represents a plurality, the same applies hereinafter). Is composed. The cylinder center line points in the front-rear direction of the outboard motor.
A cylinder head 2e is provided behind the cylinder block 2d, and a cylinder head cover 2f is further provided behind the cylinder head 2e. A crankcase 2g is provided in front of the cylinder block 2d. The above constitutes an engine assembly.
[0031]
The cylinders 2b, pistons 2c, and cylinder head 2e of each cylinder of the engine 2 constitute a combustion chamber 2h.
Each combustion chamber 2h communicates with an exhaust port 2i provided in the cylinder head 2e, and an exhaust manifold 3 is vertically arranged outside the cylinder head 2e so as to face the exhaust port 2i. An oil pump body is provided below the engine 2.
The above engine assembly is supported on the oil case 5 by the mount case 4. The oil case 5 forms an oil pan section 5c and an exhaust chamber 17 described later, and contains an oil suction pipe 5a and an oil strainer 5b in the oil pan section 5c.
[0032]
The above-described crankshaft 2a in the vertical direction of the engine 2 is located in a forward portion on the right side in FIG. 1 as a whole of the outboard motor.
An output shaft 2j is connected to a lower end portion of the crankshaft 2a via a flywheel (not shown). The output shaft 2j extends vertically through the mount case 4 and is arranged vertically, and the drive shaft 6 is coaxially arranged. It is connected to the upper end.
[0033]
The drive shaft 6 hangs downward between the lower oil pan 5 and the peripheral wall, extends, and drives an output shaft 8 a extending rearward through a transmission and transmission mechanism 7. .
The propeller 8 is connected to the rear end of the output shaft 8a, the drive shaft 7 is driven by the engine 2, and the propeller 8 is driven via the transmission and the speed change mechanism 7 to obtain thrust.
[0034]
The above and surroundings of the engine 2 are covered so as to be surrounded by an engine cover 9 made of resin. The engine cover 9 covers a middle part to an upper part in the vertical direction of the engine 2 and includes a lower half part of the engine 2 to a pump body. The periphery and upper and lower sides of the mount case 4 are covered with a resin under cover 10 arranged below the engine cover 9.
An extension case 11 is continuously provided below the oil case 5, and a gear box 12 is integrally provided below the extension case 11. The gear box 12 containing the extension case 11 and the speed change mechanism 7 is made of aluminum alloy or the like. The drive shaft 6 vertically passes through a forward portion of this inside.
The undercover 10 covers a mating surface of the oil case 5 and the extension case 11.
[0035]
The mount case 4 including the above-described pump body and its peripheral portion are formed of a metal such as an aluminum alloy. A swivel shaft 13a is installed vertically between the front part of the mount case 4 and the intermediate part of the front part of the extension case 11, and the stern bracket 14 can be vertically pivoted on the tilt shaft 14a via the swivel case 13. connect.
That is, the swivel case 13 tilts around the tilt shaft 14a with respect to the stern bracket 14 fixed to the stern, so that the outboard motor 1 is mounted on the stern of the hull so as to be steerable and tiltable (up and down). Is done.
[0036]
By the way, the exhaust manifold 3 connects the downwardly directed exhaust portion 3a at the lower portion thereof to a communication port 15 provided vertically adjacent to the rear of the oil pan 5 of the mount case 4, and the communication port 15 is connected to the communication port 15. The exhaust portion 3a is communicated with and connected to an exhaust pipe 16 which is suspended downward from a rear portion of the mount case 4 and installed.
These form an exhaust passage.
[0037]
The inside of the under cover 10 is vertically divided by a mount case 4 arranged in the front-rear direction, and a space partitioned vertically with an engine room 18 is formed below the mount case 4, and the exhaust pipe 16 is suspended in the space. Face to do.
The above-mentioned space below and around the exhaust pipe 16 forms an exhaust expansion space 17. At the rear of the engine room 18 divided by the mount case 4 in the upper and lower parts, a communication path 19 communicating the chambers (spaces) 17 and 18 divided by the mount case 4 is provided.
[0038]
The communication path 19 is installed vertically in the rear part 4 a of the mount case 4. A base of a substantially inverted L-shaped exhaust pipe 20 is attached to the communication passage 19 by bolts.
The exhaust pipe 20 is an external exhaust pipe that discharges engine exhaust to the outside. A rear end 20a of the external exhaust pipe 20 that opens substantially horizontally rearward is provided on a rear surface of the under cover 10 as described later. It is led out rearward from the opening 50.
Normally, the engine exhaust is discharged from the exhaust manifold 3 through the communication port 15 to the exhaust expansion space 17 from the exhaust pipe 16 hung downward, and is discharged into the water through the extension case 11.
[0039]
In the illustrated embodiment, the external exhaust pipe 20 is connected to the communication path 19 provided at the rear of the mount case 4, but instead of the mount case 4, the rear of the oil pan 5 in FIG. It may be extended, and a communication passage may be installed longitudinally in this extension portion, and the external exhaust pipe 20 may be connected to the communication passage.
[0040]
By the way, when the exhaust pressure of the engine is low, such as during idling operation, the exhaust gas cannot be discharged through the water.
On the other hand, the exhaust gas is discharged into the exhaust expansion space 17 via the exhaust pipe 16. In this case, the exhaust gas is discharged from the external exhaust pipe 20 to the outside of the under cover 10 through the communication port 19.
As described above, when the exhaust pressure of the engine is low, such as during idling operation, the external exhaust pipe 20 serves to discharge exhaust from the exhaust pipe 20 to the outside.
[0041]
In FIG. 1, reference numeral 21 denotes an intake passage device, and reference numeral 22 denotes a connecting portion 22 at an upper intermediate portion of the left and right intake passages. In FIG. 1, only one intake passage 24 is shown. The other intake passage is disposed on the near side in the front and back direction of the drawing.
An outside air intake opening 25 provided at the rear of the top of the engine cover 9 is a first outside air intake opening 25a elongated in the left-right direction at the rear upper end of the top piece 9a, and an upward opening at the middle part in the front-rear direction. It comprises a second outside air intake opening 25b and a gallery-like third outside air intake opening 25c in front of the opening.
[0042]
FIG. 2 is a perspective view of the rear part of the under cover, and is an exploded perspective view showing a state immediately before the attachment of the sealing means.
The undercover 10 includes left and right halves 10L and 10R, and left and right symmetrical concave portions 10a and 10a are formed in upper to middle portions of the joining edges 10c and 10c on the rear surface. Are formed into a vertically long opening 50 on the rear surface. At the upper ends of the joined half bodies 10L and 10R, an engagement piece 10b that fits with the lower edge of the upper engine cover 9 is installed upright.
[0043]
At the periphery of the opening 50, a seating surface 51 is provided so as to surround the opening 50, and mounting holes 52 are provided at four corners of the seating surface and near the periphery.
The ignition plug 2p of the lowest cylinder of the engine 2 faces the large opening 50a above the opening 50, and the rear end 20a of the external exhaust pipe 20 faces the small opening 50b below.
[0044]
The above opening 50 is closed by a sealing means.
The sealing means has a lid shape in the embodiment, and the lid 30 will be described with reference to FIGS.
3 is a front perspective view of the lid, which is a sealing means, facing the rear of the outboard motor, FIG. 4 is a rear perspective view of the same, and FIG. 5 is a vertical sectional view of the same. Referring to these drawings, the lid 30 is formed of flexible rubber.
The lid 30 has a plate shape that completely covers the opening 50 and entirely covers the seating surface 51.
[0045]
In the embodiment, five lateral concave grooves 32 are provided on the surface 31a of the substrate 31 of the lid 30 at intervals in the up and down direction to facilitate bending in a direction perpendicular to the length direction. Are provided with six mounting holes 33 on the left and right sides, the left and right sides of the lower end part, and the left and right sides of the middle part. Thereby, a holding portion for the lid, which is the sealing means, for the undercover 10 is formed.
A small edge-shaped rib 34 is provided on the periphery of the back surface 31b of the substrate 31 so as to surround the same, and a vertically long loop-shaped seal surrounding the periphery of the opening 50 is provided inside the rib 34. The lip 35 is formed integrally.
[0046]
The vertically long loop-shaped seal lip 35 constitutes a first seal portion, and the seal lip 35 is formed in a continuous loop shape with an interval outside the opening edge of the opening 50 and is shown in FIG. Thus, the tip 35a of the seal lip 35 is formed obliquely so as to face outward.
In addition, at the portion near the left and right sides of the back surface 31b of the substrate 31 and at an intermediate portion between the upper and lower mounting holes 33, there are provided four locking projections 36 at intervals in the vertical direction, which will be described later. .
[0047]
The upper portion of the lid 30 surrounded by the seal lip 35 on the rear surface 31b of the substrate 31 protrudes in the rear surface direction, fits tightly into the large opening 50a above the opening 50, and closes the opening. An elastic seal block portion 37 elastically abuts and seals a portion of the lowermost cylinder facing the opening 50a for inserting a tool of the ignition plug 2p.
A cylindrical seal portion 38 constituting a cylindrical portion serving as a second seal portion is integrally provided at a lower middle portion of the substrate 31 so as to penetrate the front and back of the substrate 31.
[0048]
The cylindrical seal portion 38 has a smaller amount of protrusion of the substrate 31 to the front surface 31a than that of the back surface 31b. As is apparent from FIG. Since the lower portion is located forward of the lower portion, the upper portion is disposed to be inclined backward, and the axis c of the cylindrical seal portion 38 is disposed substantially horizontally.
The rear portion 38a of the cylindrical seal portion 38 has a small amount of projection to the front surface 31a, and most of the rear portion 38a projects as a cylindrical main body portion 39 in a straight cylindrical shape on the back surface 31b into the engine room for a predetermined length.
[0049]
The rear portion 38a of the lid 30 projecting rearward from the surface 31a of the substrate 31 is set obliquely so as to be substantially parallel to the surface of the substrate 31 with the opening surface 38b mounted, and slightly protrudes from the surface 31a. When water invades from the opening 38c, it is difficult to enter the water, and the lower half 38d of the opening 38c is inclined rearward and downward to facilitate die-cutting at the time of forming a cylindrical portion that is an oblique hole with respect to the surface of the substrate 31. I have to.
In the embodiment, as shown in FIGS. 3 and 6, the opening of the rear portion 38a projecting rearward from the surface 31a of the substrate 31 is formed slightly vertically.
[0050]
The cylindrical main body portion 39 protruding forward from the back surface 31b of the substrate 31, that is, into the engine room, has a substantially horizontal cylindrical shape with substantially the same diameter over its entire length, and extends from a middle portion to a front portion in the longitudinal direction. A plurality of ring-shaped seal lips 40 projecting radially inward over the portion are provided at a slight interval in the axial direction.
The ring-shaped small-diameter portions 40a and 40b at both ends in the axial direction provided on the inner periphery 40 of the cylindrical main body 39 have convex inner surfaces. This portion holds the outer periphery of the exhaust pipe 20.
[0051]
By the way, 40c... Provided between the small diameter portions 40a and 40b on the inner periphery 40 of the cylindrical main body portion 39 are a plurality of ring-shaped flexible lip portions. In the embodiment, three flexible lip portions 40c are provided. , 40c, 40c are provided slightly apart from each other in the axial direction, and each lip portion 40c, 40c, 40c has an inner diameter end (tip) facing rearward, and has an inner diameter larger than that of the small diameter portions 40a, 40b. The amount of protrusion in the direction is set large.
The inlet 40d at the front end of the main body 39 is set so that its diameter is diagonally expanded forward (toward the engine room).
[0052]
In FIG. 2, the substrate 31 of the lid 30 faces the opening 50 on the rear surface of the back surface 31 b of the undercover 10, and the peripheral portion of the back surface 31 b of the substrate 31 is brought into contact with the seating surface 51 so as to close the opening 50.
The elastic seal block portion 37 on the back surface of the lid 30 is fitted into the large opening portion 50a above the opening portion 50, and the main body portion 39 at the front of the cylindrical seal portion 38 is connected to the small opening portion 50b below the opening portion 50. The main body portion 39 of the cylindrical seal portion 38 is fitted to the rear portion 20b of the external exhaust pipe 20 provided rearward.
[0053]
Thereafter, the lid 30 is pressed against the seating surface 51, and the mounting pins 41 are inserted through the six mounting holes 33, the mounting holes on the upper and left sides of the seating surface 51, the mounting holes on the middle and left and right, and the six mounting holes on the lower left and right sides. 52a. On the other hand, the locking projections 36 projecting from the rear surface 31b of the substrate 31 are passed through the mounting holes 52b on the left and right of the intermediate portion and locked.
Thus, the lid 30 is attached to the seating surface 51 on the rear surface of the undercover 10 while closing the opening 50.
[0054]
In the above, the small-diameter portions 40a and 40b of the inner periphery 40 of the cylindrical main body portion 38 of the cylindrical seal portion 38 abut on the outer periphery of the external exhaust pipe 20 and the clearance between the small-diameter portions 40a and 40b of the inner peripheral surface 40 of the cylindrical main body 39. Is kept substantially constant.
Due to this clearance, the lips 40, 40c, and 40c substantially uniformly contact the outer periphery of the external exhaust pipe 20 all around, thereby ensuring a predetermined sealing property.
In addition, the entire cylindrical main body portion 39 bends and swings with respect to the substrate 31 of the lid 30, and the cylindrical portion itself also bends, so that it can be stretched between the edge of the opening 50 and a conventional packing. , It does not stretch.
[0055]
The seal lip 35 provided on the rear surface of the substrate of the lid 30 constitutes a first seal, and the cylindrical main body 39 of the cylindrical seal 39 bends with respect to the substrate 31, and the deflection absorbing portion is formed by the bending of the cylindrical main body itself. Is composed.
Further, the above-mentioned seal lips 40, 40c, 40c formed on the inner periphery 40 constitute a second seal portion.
[0056]
FIG. 6 is a view of the undercover 10 with the lid 30 attached thereto as viewed from the rear.
The mounting state will be described below.
7 is a sectional view taken along the line 7-7 in FIG. 6, in which the locking pin is being locked, and FIG. 8 is a view showing a locked state by the locking pin.
The expanding clip 42 is inserted through the mounting holes 33 and 52a. The expanding clip 42 has a flange portion 42a at an outer end thereof, and the clip 42 is formed by a concave portion 33a provided at the outer end of the mounting hole 33 on the lid 30 side. Is supported.
This state is shown in FIG.
[0057]
By inserting the shaft portion 41a of the locking pin 41 into the expanding clip 42 and pushing it in, the stenosis portion 42b of the expanding clip 42 expands, and as shown in FIG. Inside the cover of the mounting holes 52a on the seating surface 51 side, the diameter becomes sufficiently larger than the hole diameter, and the escape is restricted.
The outer peripheral ribs 34 formed on the back surface of the lid 30 are elastically deformed and tightly sealed around the periphery of the seating surface 51, and the inner seal lip 35 is elastically deformed and abuts on the seating surface 51. The tip portion 35a faces the seat surface 51 facing outward to obtain a high sealing effect.
[0058]
FIG. 9 is a cross-sectional view taken along line 9-9 of FIG. 6 and shows a state immediately before locking by the locking projection, and FIG. 10 shows a locked state by the locking projection.
The locking projections 36 projecting from the back surface of the substrate 31 of the lid 30 are provided with a neck 36c having a diameter slightly smaller than the inner diameter of the mounting holes 52b formed in the seating surface 51 of the opening 50 as shown in FIG. It comprises an inverted trapezoidal locking portion 36a having a diameter sufficiently larger than the hole 52b, and a concave portion 36b formed inside the locking portion 36a and opened to the front end.
[0059]
When the lid 30 is brought into contact with the seat surface 51 and brought into close contact therewith, the locking projections 36 are fitted into the mounting holes 52b. The engaging projections 36a are sufficiently larger than the inner diameter of the mounting holes 52b, but are bent radially inward upon insertion and enter the mounting holes 52b.
Upon entry, the locking portion 36a is easily bent radially inward by the concave portion 36b, fits in the mounting holes 52b, and the neck portion 36c faces the mounting hole 52b.
[0060]
As shown in FIG. 10, the large-diameter locking portion 36a that has bent inward in the radial direction and passed through the inside of the mounting hole 52b leaves the restraint of the external shape, expands to the original shape, and has a seating surface of the mounting hole 52b. Since it protrudes to the back surface side of 51, it is prevented from coming out of the mounting hole 52b.
The above-mentioned seal lip 35 elastically adheres to the seating surface 51, its tip portion 35a expands and adheres outward, and the elastic rib 34 on the outer peripheral edge elastically contacts the peripheral portion of the seating surface 51. Adhered to form a double inner and outer seal structure.
[0061]
FIG. 11 is an enlarged longitudinal sectional side view of a main part showing a state in which the external exhaust pipe 20 is fitted into and sealed to a cylindrical seal portion 38 formed on the lid 30.
As described above, when attaching the lid 30 to the seat surface 51 so as to close the opening 50, the cylindrical seal portion 38 is inserted through the rear portion of the external exhaust pipe 20. At the time of insertion, the introduction port 40d at the front end of the tubular main body 39 is expanded forward (toward the engine room), so that the rear end 20a of the external exhaust pipe 20 can be easily and smoothly inserted. Can be performed reliably.
[0062]
The outer peripheral portion 20b of the outer exhaust pipe 20 presses the ring-shaped small-diameter portion 40b at the front of the seal lip 40 formed on the inner periphery of the cylindrical main body portion 39 to elastically deform, and a plurality of axially outer portions. The ring-shaped flexible lip portions 40c advance in the inner peripheral portion while being bent backward (outward), and the rear end faces the rear portion 38a of the cylindrical seal portion 38 via the small diameter portion 40a.
The rear end face 20c of the external exhaust pipe 20 protrudes slightly outside from the opening 38c at the rear end of the cylindrical seal portion 38.
[0063]
In the above description, in the cylindrical seal portion 36, the outer peripheral portion 20b of the external exhaust pipe 20 is made to have a substantially uniform distance between the inner peripheral surface of the cylindrical seal portion and the outer peripheral portion 20b of the external exhaust pipe 20 by the small diameter portions 40a and 40b. The flexible lip portions 40c, 40c, 40c between them substantially uniformly contact and seal the outer peripheral portion 20b, and the flexible lip portions 40c, 40c, 40c bend so as to face outward (outside the cover). Therefore, even if the inside of the engine room 18 becomes a negative pressure, it is possible to maintain and secure a high sealing property.
[0064]
FIG. 12 is a vertical sectional side view showing another embodiment of the seal structure of the present invention.
In this embodiment, the cover member 130 and the seal member 138 of the outboard motor are formed separately and integrated. The seal member is formed of a flexible rubber.
The cover 130 of the outboard motor is provided with a through-hole 130a, into which the peripheral portion of the seal member 138 is fitted and integrated.
The sealing member 138 has a tubular portion 139 at the center, and is formed in an umbrella shape that is expanded toward the front (in the direction of the engine room 18 and inside the cover) at the rear end of the tubular portion, and has a length in the axial direction. A ring-shaped concave groove 141 is provided on the outer periphery of the peripheral portion 138b having the peripheral portion 138b, the ring-shaped concave groove 141 is fitted into the inner periphery of the through hole 130a of the cover member 130, and the peripheral portion 138b is sealed. It is mounted on the cover member 130 while maintaining the properties.
[0065]
Further, in the present embodiment, the seal configuration around the through hole of the cover is simple, but the through hole is provided in the lower area defined by the mount case of the cover body, that is, outside the engine room. Under a condition in which the intake negative pressure of the engine does not affect, such as when the exhaust pipe 20 protrudes from the exhaust chamber 17, an inexpensive configuration can be achieved while effectively maintaining the sealing function.
[0066]
A connecting portion 138c is formed between the peripheral portion 138b and the rear end of the cylindrical portion 139, and the rear end of the peripheral portion 138 and the rear end of the cylindrical portion 139 at the connecting portion 138c are bent. The cylindrical portion 139 is easily bent with respect to the peripheral portion 138b at this portion, and the connecting portion 138c constitutes a bias absorbing portion.
By the way, the inner peripheral portion 140 of the cylindrical portion 139 is provided with the same flexible lip portions 140c, 140c, 140c and the small diameter portion 140b as described above, and holds and seals the inserted external exhaust pipe 20. .
[0067]
In the foregoing, the illustrated embodiment has been described. In the embodiment, the sealing means is attached to the opening of the under cover which is the cover member. Alternatively, the sealing means may be attached and supported on the side of the external exhaust pipe.
Although the sealing means is a member fitted into the lid or the opening of the cover member, the specific shape and structure are arbitrary. If necessary, the sealing means can be attached to either the cover member or the external exhaust pipe. May be provided, and a deviation absorbing unit may be provided.
Further, the exhaust pipe may be fitted to the mount case to ensure the positioning. Even in this case, the absorption of the displacement due to the bending of the resin cover body is achieved.
The exhaust gas may be of a type that is entirely discharged into the atmosphere.
[0068]
【The invention's effect】
The present invention has the following effects by the above configuration.
Claim 1 is a seal structure for an exhaust pipe of an outboard motor, comprising an engine and a propeller driven by the engine, a part of which is supported by a main body case, and the engine is covered by a cover member. In the outboard motor, an exhaust pipe that makes at least a part of the exhaust of the engine in the air is provided in the main body case, and an end of the exhaust pipe protrudes outward from an opening provided in the cover member. A seal is provided for sealing between the cover member and the exhaust pipe. The seal means includes a holding portion held by either the cover member or the exhaust pipe, a first seal portion in contact with the cover member, and an exhaust pipe. A second sealing portion that is in contact with the first sealing portion; and a deviation absorbing portion between the holding portion and any of the sealing portions.
[0069]
According to the first aspect, in the outboard motor, at an opening that protrudes the exhaust pipe to the outside of the cover member, a sealing means that is held by the cover member or the like and seals between the cover member and the exhaust pipe is provided. It is held by a holding part on either the cover member or the exhaust pipe, the periphery of the opening is sealed by the first seal part, the exhaust pipe is sealed by the second seal part, and the phase deviation is absorbed by the non-uniform absorption part. You.
The resin cover member and the metal may be held at any one of the holding portions between the sealing means and the cover member, between the cover member and the first seal portion, and between the exhaust pipe and the second seal portion. Even if errors such as manufacturing errors and assembly errors occur in the sealing means between the exhaust pipe installed on the base made of steel, these errors are absorbed and the gap between the cover member and the exhaust pipe that performs external exhaust is absorbed. High sealing performance can be secured.
Since the above can be achieved only by providing a deviation absorbing portion such as a bent portion, effective absorption of phase shift and high-precision sealing can be performed with a simple structure.
[0070]
According to a second aspect of the present invention, in the first aspect, the holding portion is located substantially at the opening of the cover member so as to hold the sealing means against the opening of the cover member, and the offset absorbing portion has an opening. The cover member is provided inside or outside the cover member.
[0071]
According to the second aspect, in addition to the effect of the first aspect, the holding portion of the sealing means holds it around the opening of the cover member, and the bias absorbing portion is more inward than the surface of the opening of the cover member. Or, since it is provided on the outside, it is possible to easily set the displacement absorbing capacity of the bent portion which is the displacement absorbing portion easily.
Therefore, even if errors such as a manufacturing error of the resin cover member and an assembly error between the resin base member and the metal base occur, these errors are absorbed and the height between the cover member and the exhaust pipe for external exhaust is increased. Sealability can be ensured.
[0072]
According to a third aspect of the present invention, in the first aspect, the holding portion is located substantially at the opening of the cover member so as to hold the sealing means with respect to the opening of the cover member, and the sealing portion is provided on a surface on which the opening is formed. Generally, the offset absorbing portion is provided inside or outside the cover member with respect to the surface.
[0073]
According to a third aspect of the present invention, in addition to the effect of the first aspect, the holding portion of the sealing means holds it around the opening of the cover member, and the sealing portion is disposed on the surface where the opening is formed. Since the offset absorbing portion of the portion is provided inside or outside the surface of the opening of the cover member, the displacement absorbing capacity can be easily set to be large for the bent portion which is the displacement absorbing portion.
Therefore, even if errors such as a manufacturing error of the resin cover member and an assembly error between the resin base member and the metal base occur, these errors are absorbed and the height between the cover member and the exhaust pipe for external exhaust is increased. Sealability can be ensured.
[0074]
A fourth aspect of the present invention is characterized in that, in any one of the first to third aspects, the offset absorbing portion absorbs displacement due to bending.
[0075]
According to the fourth aspect, in addition to the effect of any one of the first to third aspects, since the deviation absorbing part absorbs the deviation by bending, a deviation between the exhaust pipe, the sealing means, and the first and second sealing parts is provided. , And the deviation during this time can be reliably and easily absorbed.
Therefore, even if errors such as a manufacturing error of the resin cover member and an assembly error between the resin base member and the metal base occur, these errors are absorbed and the height between the cover member and the exhaust pipe for external exhaust is increased. In addition, since the sealing performance of the present invention can be ensured, and the displacement absorbing portion has a flexible structure, the structure is simple and a high and reliable displacement absorbing action can be obtained.
[0076]
According to a fifth aspect of the present invention, in any one of the first to fourth aspects, the cover member constitutes a part of an engine room accommodating the engine, the opening is provided facing the engine room, and the exhaust pipe is provided. It is provided so as to penetrate the opening from the inside of the engine room to the outside of the cover member, and the seal portion is provided at a position separated from the edge of the opening.
[0077]
According to the fifth aspect, the seal portion of the seal member that seals the opening of the cover member that is a part of the engine room is provided at a position separated from the edge of the opening. A sufficient space is formed. Therefore, water that may enter from the periphery of the opening of the cover member through the seal portion enters only through a wide space between the opening and the opening portion. Hydrophilicity can be obtained.
[0078]
According to a sixth aspect of the present invention, in the first aspect, the case body is a mount case that supports the engine, the sealing means is a lid that closes an opening of the cover member, and the holding part is a lid around the opening of the cover member. The first seal portion is provided on the back surface of the cover member, surrounds the opening of the cover member, and is in contact with the periphery of the opening. The tube was structured to be held flexibly with respect to the lid.
[0079]
In claim 6, in addition to the effect of claim 1, the exhaust pipe supported by the mount case is led out from the opening of the cover member as an external exhaust pipe, and the opening is closed with a lid fixed to the cover member. Since the first seal portion on the back surface of the cover member seals the periphery of the opening, the second seal portion seals the outer periphery of the exhaust pipe, and the bias absorbing portion holds the exhaust pipe with respect to the lid with flexibility. By the bending of this portion, a phase shift (bias or deviation) generated between the exhaust pipe supported by the metal mount case and the resin cover member can be absorbed.
Therefore, the lid is attached to the opening of the cover member so as to close the lid, the opening is sealed with the first seal portion provided on the lid, and the exhaust pipe is held with flexibility by the bias absorbing portion with respect to the lid. Since the outer periphery of the exhaust pipe is sealed by the two sealing portions, the sealing of the exhaust pipe for exhausting the gas to the outside of the cover member can be performed with a simple structure and with a minimum number of components.
[0080]
According to a seventh aspect, in the sixth aspect, the offset absorbing portion is a tubular portion fitted to the exhaust pipe, is provided so as to intersect the surface of the lid, and comes into contact with the outer periphery of the exhaust pipe at the inner periphery of the tubular portion. A second seal comprising a flexible seal lip was provided, and the tubular portion was formed integrally with the lid.
[0081]
According to the seventh aspect, in addition to the effect of the sixth aspect, the exhaust pipe can be sealed by passing the exhaust pipe through a cylindrical portion provided on the lid for sealing by closing the opening of the cover member, Since the cylindrical portion bends with respect to the lid, the phase shift (bias, deviation) generated between the exhaust pipe supported by the metal mount case as a deviation absorbing portion and the resin cover member is cylindrical. It can be absorbed by bending of the part.
Therefore, a high sealing property can be obtained when the exhaust pipe is led out of the exhaust pipe, and a eccentric absorption section is formed by the tubular section, and a flexible seal lip section is provided on the inner periphery of the tubular section as a second seal section to contact the outer periphery of the exhaust pipe. The structure of the deviating absorbing part and the second seal part is simple and can be easily manufactured, and the inner peripheral part of the tubular part which is the deviating absorbing part is in contact with the outer periphery of the exhaust pipe. Since a flexible seal lip is provided and sealed with this, and the displacement of the exhaust pipe is absorbed by the deflection of the tubular portion (deviation and deviation), an effective displacement absorption structure can be obtained.
[0082]
According to claim 8, in claim 1, the offset absorbing portion includes a tubular portion that is attached to the cover member via a seal portion, is continuous with the offset absorbing portion, and fits and holds the exhaust pipe. A second seal including a flexible seal lip portion that comes into contact with the outer periphery of the exhaust pipe is provided on the inner periphery of the shape portion.
[0083]
According to the eighth aspect, in addition to the effect of the first aspect, a seal member is attached to the exhaust pipe lead-out opening provided in the cover member via a seal portion, and the bias absorbing portion fits and holds the exhaust pipe. Phase deviation (deflection, deviation) generated between the exhaust pipe supported by the metal mount case as a deviation absorbing portion and the resin cover member, and the deflection of the cylindrical portion. Can be absorbed.
Moreover, the seal between the exhaust pipe and the tubular portion can be maintained at a high level by the flexible seal lip.
Then, a deviation absorbing portion may be provided in a disk shape around a part of the cylindrical portion provided with the seal lip therein, and fitted and attached to an opening of a case member provided with a seal portion on the outer periphery thereof. Therefore, it is possible to obtain a seal structure of the exhaust pipe of the outboard motor which is extremely excellent in function, with simple structure, simple mounting work, and functionally.
[0084]
According to a ninth aspect, in the seventh or eighth aspect, the flexible seal lip portion of the second seal portion provided in the cylindrical portion has a ring shape, and a tip portion that contacts the exhaust pipe faces outward. A plurality were provided apart from each other in the axial direction.
[0085]
According to claim 9, in addition to the effect of claim 7 or claim 8, the outer circumference of the exhaust pipe is bound, so to speak, by a ring-shaped flexible seal lip portion, and the binding is also separated at a plurality of locations in the axial direction, Since the tip of the seal lip faces outward, even if the negative pressure in the engine room acts outward through the exhaust pipe, the seal lip does not turn inward, and the seal lip does not turn. , A high degree of sealing can be ensured, and high waterproofness of the sealing portion of the exhaust pipe led out can be ensured.
In addition, a plurality of seal lips may be provided in a ring shape on the inner periphery of the cylindrical portion, and the tip may be directed outward in the axial direction, so that the structure is simple and the production is easy.
[0086]
According to a tenth aspect, in the sixth aspect, the first seal portion provided on the back surface of the cover member surrounds the opening, and is provided at a position separated from an edge of the opening, and is formed as a seal lip portion. The tip of the portion, which is in contact with the periphery of the opening, is provided to face outward of the opening.
[0087]
According to the tenth aspect, the first seal portion provided on the back surface of the cover member surrounds the opening, is formed as a seal lip at a position separated from the edge of the opening, and has a peripheral portion around the opening of the seal lip. Since the contact tip is provided so as to face the outside of the opening, the cover member is excellent in waterproofness and intrusion resistance against water that may enter from the periphery of the opening of the cover member.
Further, the above is formed as a seal lip on the back surface of the lid at a position separated from the edge of the opening, and the tip contacting the periphery of the opening of the seal lip is formed so as to face outward of the opening. Therefore, it is possible to obtain a sealing means that can ensure a high degree of sealing performance with a simple structure and easy production.
[Brief description of the drawings]
FIG. 1 is an explanatory overall side view of an outboard motor in which essential parts are cut away.
FIG. 2 is an exploded perspective view of a rear portion of an under cover, showing a state immediately before attachment of a sealing means.
FIG. 3 is a front perspective view of a lid serving as a sealing means, which faces the rear of the outboard motor.
FIG. 4 is a rear perspective view of the lid.
FIG. 5 is a longitudinal sectional view of a lid.
FIG. 6 is a rear view of the undercover with a lid serving as a sealing means attached thereto.
FIG. 7 is a sectional view taken along line 7-7 of FIG.
8 is a view showing a state in which the lid is locked by the locking pin in FIG. 7;
9 is a cross-sectional view taken along line 9-9 of FIG.
FIG. 10 is a diagram showing a locked state by a locking projection in FIG. 9;
FIG. 11 is an enlarged vertical cross-sectional view of a main part showing a state in which the external exhaust pipe is fitted into a cylindrical seal portion formed on a lid of the lid and a sealed state is shown.
FIG. 12 is a longitudinal sectional side view showing another embodiment of the seal member.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Outboard motor, 2 ... Engine, 8 ... Propeller, 4 ... Mount case which is a main body case, 9, 10 ... Cover member, 20 ... External exhaust pipe which is an exhaust pipe, 50 ... Opening, 30 ... Sealing means Certain lids, 33, 36, 41: holding portion, 35: first sealing portion, 38: second sealing portion, 39: offset absorbing portion, 40c: sealing lip portion.

Claims (10)

エンジンと、該エンジンで駆動されるプロペラとを備え、これらの一部をケース体で支持し、前記エンジンをカバー部材で覆った船外機において、
前記エンジンの排気の少なくとも一部を空中に排気する排気管を前記ケース体に設け、
前記排気管の端部を、前記カバー部材に設けた開口部から外方に突き出すとともに、前記開口部には、前記カバー部材と前記排気管との間をシールするシール手段を備え、
前記シール手段には、前記カバー部材または前記排気管の何れかに保持される保持部と、前記カバー部材に接する第１シール部と、前記排気管に接する第２シール部と、前記保持部と前記シール部の何れかとの間の偏寄吸収部とを、
備えることを特徴とする船外機の排気管のシール構造。An outboard motor comprising an engine and a propeller driven by the engine, a part of which is supported by a case body, and the engine is covered by a cover member.
An exhaust pipe for exhausting at least a part of the exhaust of the engine into the air is provided in the case body,
An end of the exhaust pipe projects outward from an opening provided in the cover member, and the opening includes sealing means for sealing between the cover member and the exhaust pipe.
The sealing means includes a holding portion held by either the cover member or the exhaust pipe, a first seal portion in contact with the cover member, a second seal portion in contact with the exhaust pipe, and the holding portion. A bias absorbing portion between any of the seal portions,
A seal structure for an exhaust pipe of an outboard motor, comprising: 前記保持部は、前記カバー部材の開口部に対してシール手段を保持するように、前記カバー部材の開口部に概ね位置し、前記偏寄吸収部は、前記開口部を形成した面よりカバー部材内方または外方に設けられていることを特徴とする請求項１記載の船外機の排気管のシール構造。The holding portion is generally positioned at the opening of the cover member so as to hold the sealing means with respect to the opening of the cover member, and the offset absorbing portion is provided on the cover member from a surface on which the opening is formed. The seal structure for an exhaust pipe of an outboard motor according to claim 1, wherein the seal structure is provided inside or outside. 前記保持部は、前記カバー部材の開口部に対してシール手段を保持するように、前記カバー部材の開口部に概ね位置し、前記シール部は、前記開口部を形成した面に概ねあり、前記偏寄吸収部がその面よりもカバー部材内方または外方に設けられていることを特徴とする請求項１記載の船外機の排気管のシール構造。The holding portion is generally located at the opening of the cover member so as to hold the sealing means with respect to the opening of the cover member, and the sealing portion is substantially on the surface where the opening is formed, The exhaust pipe sealing structure for an outboard motor according to claim 1, wherein the offset absorbing section is provided inside or outside the cover member with respect to the surface. 前記偏寄吸収部は、撓みによるズレ吸収を行なうことを特徴とする請求項１〜請求項３の何れかに記載の船外機の排気管のシール構造。The seal structure for an exhaust pipe of an outboard motor according to any one of claims 1 to 3, wherein the offset absorbing portion absorbs displacement due to bending. 前記カバー部材が前記エンジンを収容するエンジンルームの一部を構成し、前記開口部が該エンジンルームに臨んで設けられており、前記排気管が該エンジンルーム内からカバー部材外方に前記開口部を貫通するように設けられており、前記シール部が前記開口部の縁から離間した箇所に設けられていることを特徴とする請求項１〜請求項４の何れかに記載の船外機の排気管のシール構造。The cover member forms a part of an engine room that houses the engine, the opening is provided facing the engine room, and the exhaust pipe extends from the engine room to the outside of the cover member. The outboard motor according to any one of claims 1 to 4, wherein the outboard motor is provided so as to penetrate the opening portion, and the seal portion is provided at a position separated from an edge of the opening portion. Exhaust pipe seal structure. 前記ケース体はエンジンを支持するマウントケースであり、前記シール手段は前記カバー部材の開口部を閉塞するリッドであり、前記保持部は該リッドをカバー部材の開口部周辺部に固定する固定部材であり、前記第１シール部はカバー部材の裏面に設けられ、前記カバー部材の前記開口部を囲繞し、該開口部周辺部に接触するシール部であり、前記偏寄吸収部は、前記排気管を該リッドに対して可撓性をもって保持する構造であることを特徴とする請求項１記載の船外機の排気管のシール構造。The case body is a mount case that supports an engine, the sealing unit is a lid that closes an opening of the cover member, and the holding unit is a fixing member that fixes the lid to a periphery of the opening of the cover member. The first seal portion is provided on a back surface of the cover member, surrounds the opening of the cover member, and is in contact with a peripheral portion of the opening, and the bias absorbing portion includes the exhaust pipe. 2. A seal structure for an exhaust pipe of an outboard motor according to claim 1, wherein said seal structure is configured to flexibly hold said lid to said lid. 前記偏寄吸収部は、前記排気管に嵌合する筒状部であり、前記リッドの面に対し交わるように設けられ、該筒状部内周に前記排気管外周に接触する前記可撓性シールリップ部からなる第２シールを備え、該筒状部は、前記リッドと一体に形成したことを特徴とする請求項６記載の船外機の排気管のシール構造。The bias absorbing portion is a tubular portion fitted to the exhaust pipe, is provided so as to intersect with a surface of the lid, and has an inner periphery of the tubular portion and the flexible seal contacting the outer periphery of the exhaust pipe. The exhaust pipe seal structure for an outboard motor according to claim 6, further comprising a second seal including a lip portion, wherein the tubular portion is formed integrally with the lid. 前記偏寄吸収部は、前記カバー部材にシール部を介して装着され、該偏寄吸収部と連続し、排気管を嵌合、保持する筒状部を備え、該筒状部内周に前記排気管外周に接触する可撓性シールリップ部からなる第２シールを備えることを特徴とする請求項１記載の排気管のシール構造。The offset absorbing portion is attached to the cover member via a seal portion, is connected to the offset absorbing portion, includes a tubular portion that fits and holds an exhaust pipe, and the exhaust portion is provided on an inner periphery of the tubular portion. 2. The exhaust pipe seal structure according to claim 1, further comprising a second seal including a flexible seal lip that comes into contact with the outer periphery of the pipe. 前記筒状部に設けた第２シール部の可撓性シールリップ部はリング状であり、排気管と接触する先端部が外方を向いて軸方向に離間して複数個設けられていることを特徴とする請求項７、または請求項８記載の船外機の排気管のシール構造。The flexible seal lip portion of the second seal portion provided in the cylindrical portion has a ring shape, and a plurality of distal end portions that come into contact with the exhaust pipe face outward and are axially separated from each other. The seal structure for an exhaust pipe of an outboard motor according to claim 7 or 8, wherein: 前記カバー部材の裏面に設けられた第１シール部は、前記開口部を囲繞し、該開口部の縁から離間した箇所に設けられてシールリップ部として形成され、該シールリップ部の該開口部周辺部と接触する先端部が該開口の外方に向いて設けられているようにしたことを特徴とする請求項６記載の船外機の排気管のシール構造。A first seal portion provided on the back surface of the cover member surrounds the opening, is provided at a location separated from an edge of the opening, and is formed as a seal lip portion, and the opening portion of the seal lip portion 7. The exhaust pipe seal structure for an outboard motor according to claim 6, wherein a front end portion which comes into contact with the peripheral portion is provided to face outward of the opening.
JP2003135049A 2003-05-13 2003-05-13 Sealing structure of exhaust pipe in outboard motor Pending JP2004339962A (en)

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JP2003135049A JP2004339962A (en) 2003-05-13 2003-05-13 Sealing structure of exhaust pipe in outboard motor
US10/839,412 US6941921B2 (en) 2003-05-13 2004-05-05 Outboard motor having seal structure for exhaust release pipe
CN200410034781.2A CN1288035C (en) 2003-05-13 2004-05-12 Outboard motor having seal structure for exhaust release pipe
US11/203,351 US7294030B2 (en) 2003-05-13 2005-08-12 Outboard motor having seal structure for exhaust release pipe

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CN1288035C (en) 2006-12-06
US6941921B2 (en) 2005-09-13
US20040226533A1 (en) 2004-11-18
US20060183386A1 (en) 2006-08-17
CN1550412A (en) 2004-12-01
US7294030B2 (en) 2007-11-13

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